Project "Might as Well Make it Right While I'm at It!"

[Yukon Jack]

This is going to be wordy so hang in there!

As some of you may recall, my Rockwell T221 transfer case in my 69 K20 got low on gear oil and took out the input bearings on the rear of the case back in March of this year.



I considered my options of repairing or putting in a spare Rockwell or putting in an NP205. As luck would have it, a while back I bought a 1984 1 ton crew cab parts truck for its front axle so I had on hand a good NP205 with adapter for an SM465. And yes, part of this overall project will include swapping in the Dana 60! Say good bye to the drum braked closed knuckle Dana 44!!!

Now initially I was bummed when the Rockwell went belly up, but in the end this is a good thing! My last major project was swapping out the 69's mighty 307 SBC for a 454 BBC from a 1989 1 Ton. As some of the seasoned members will remember, I ran into terrible firewall clearance issues - in my opinion, worse than normal. That swap project turned into the proverbial “Might as Well” project and before I knew it I had the whole truck completely disassembled and rust repairs were tackled along with a new coat of paint.

My research had told me that a 2" body lift was usually sufficient to get around BBC fitment issues. I, of course, was not smart enough to do a test fit of the cab on the frame before sending it out to get painted. Well, we got the cab all painted and when it came time to put the cab on the frame there was major firewall clearance issues! Mind you the truck was at the body shop and in the interest of time it was decided to clearance the firewall to make the BBC fit.

Even after modifying the firewall, I still had issues which required the use of more body lift than I am comfortable with.

This is where the present Rockwell problem turns out to be a good thing. I’ve decided to put in the NP205 as it just seems like the logical thing to do - newer transfer case with no parts availability problems. Well, in researching the swap I have discovered the NP205 setup with adapter is 5" longer than the Rockwell T221 setup with adapter. The location where the adapters bolt to the crossmember is 2" different. That is going to be a very good thing as that will allow me to move the BBC forward 2" which should allow me to remove my excessive body lift and reduce it down to hopefully just a 1" body lift. I believe I will be able to leave my transfer case crossmember in its current location and only have to move the engine crossmember.

In case anyone cares, here are two pics of the different transfer cases with detailed measurements. Some of these measurements were done with the Rockwell installed so if I find any inaccuracies, I will update this info.





This shows the Rockwell + adapter overall length is 14" while the NP205 + adapter overall length is 19 ½"

For anyone doing a T221 to NP205 swap, it appears the NP205's crossmember sits about 1" lower so I’m not sure if I will need to lower my crossmember or if I will be okay since I’m still going to have a slight body lift. It may be I will need to lower the transfer case to keep the engine angle/driveline angle happy.

[Yukon Jack]

From the above measurements I think I finally understand why my BBC swap had such big firewall clearance issues. Some people swap in a BBC with absolutely no firewall issues while some have to bash in the firewall just a bit to give head clearance. I had major firewall clearance issues even after cutting part of the firewall out and using an excessive body lift. The 69's transfer case crossmember is not in the same place as my 70 K5's transfer case crossmember - the 69's is forward a bit, however, the length of the two transfer case adapters is measured from the face of the adapter to the location where they bolt to the crossmember is 2" different. I believe that puts the factory Rockwell equipped 1969's engine further back towards the firewall than a later year truck.

I don’t have a specific measurement, but if the above is all correct, I think a 1969's factory SBC sits back probably 1" to 1 ½" closer to the firewall due to the Rockwell’s adapter shorter length as compared to like a 1970 - 1972 that would have had the longer NP205 + adapter. If this is correct, that definitely answers the questions of why I had such bad firewall issues.

For those that don’t remember, here’s a pic showing the drastic firewall mods that were made to my cab - even with these cuts, I still had to use an excessive body lift to make the cab fit!



Oil pan clearance for a BBC can sometimes be a problem with the 67-72 4wd’s engine crossmember. I “fixed” that issue when I originally put in the BBC by using a number of washers between the block and the motor mount to slightly raise the engine. However, this obviously didn’t help my firewall clearance issue so I decided to correct that now. I found that by jacking the engine up I was able to remove the stock engine crossmember. I took it, along with a spare 73-87 engine crossmember, to a buddy and we took two 1" pieces out of the bottom of the 73-87 crossmember and welded each piece into the sides of my factory crossmember to drop it down to get rid of the oil pan clearance issue.



Here you can see the clearance this gives



I’ve had very little time to work on this project but Saturday morning I woke up at about 5:30 a.m. and couldn’t fall back to sleep - at about 6:00 I grabbed my work clothes and my trusty pup and off we went to the shop. Unfortunately I determined that my seats had to come out for me to get my tranny hump out so I set to work getting the seats unbolted. Of course one of the bolts was a bear to remove and I don’t want to even say how long it took to get it removed - I seriously thought I was going to have to cut the nut off - it was so frozen by rust! Finally got the seats out



A while back I borrowed a friend’s motorcycle jack and it worked really well to help me remove the Rockwell transfer case



I know I’ve read some guys are able to bench press a transfer case out and in a vehicle - well, I’m not one of them!



When I initially put in the BBC and resulting body lift, I found the easiest way to get around linkage modifications was to put in a low tranny hump. I really liked having that low hump as it gives a little more room to the cab, but removing the majority of the body lift is going to necessitate going back to a high hump. No biggie, except I’ll have to address the carpet issue now - doubt there will be much demand for a fairly new low hump carpet cut for a transfer case shifter - maybe I will be able to modify this carpet and still use it - have to see about that.



My next step will be to install the NP205 adapter and then move the engine forward until the adapter’s bolt holes line up with the transfer case crossmember. I think I will grab a hydraulic jack and a long 4x4 post and put one end of the 4x4 post against my truck’s receiver hitch and then set the hydraulic jack between the other end of the 4x4 post and the transfer case adapter and slowly push the engine forward. I will have a rolling floor jack under the engine to take the weight off the engine crossmember and allow it to move forward easier. Haven’t verified that I can do it this way, but that is what I’m thinking right now.

Then I’ll remove the radiator and start removing the body lift and replace it with hopefully just a 1" body lift. The exhaust runs between the frame and the body near the rear of the cab and I believe leaving a 1" body lift will keep me from having to have my basically new exhaust totally reworked. Project funds are very tight right now so I’m hoping that works out okay.

Assuming the above works out okay, I’ll then swap in the NP205 and start figuring out how all of this has effected my driveshafts. I have a two piece rear driveshaft and of course I replaced the carrier bearing not to long ago and had all new u-joints installed. I know another boardmember did the T221 to NP205 swap not long ago and he went with a custom one piece driveshaft. Have to see how that works out for me. The rear driveshaft exits the NP205 in a totally different location than the Rockwell T221 so definitely will require changes.

The final part of the project will be swapping in the Dana 60 - that should be relatively straight forward - course that never seems to be the case with me! I might drive the truck for a while before I swap in the Dana 60 as it has been off the road for 5-6 months at this point, but I’m assuming the NP205 will require front driveshaft modifications and I won’t do that until the Dana 60 is in place.

[FormerMember]

...

[Yukon Jack]

Looked at my exhuast routing last night for a couple minutes and if I go with a 2" body lift I should be okay with the current exhaust routing, but I was kind of wanting to get down to just 1" of body lift and that would probably require removing the exhaust under the cab and having it re-done.

Here are a couple pics I took after the exhaust was installed





Guess I'll make that decision a later on - I rather not have to dish out more money on exhaust but I might find that the NP205 hits the x-pipe anyway given its longer overall length. If that occurs, then I guess that decides the issue for me!

[Tynee]

Yukon, you're in it up to your elbows again. Good luck, and have fun.

[red71cheyenne]

Looking good YJ! Hope the swap goes easier than the whole 454 shoehorn trip. Question on your exhaust routing though: With it that close to the floor, did you notice any more heat from it than running it under the tranny and xfer case? Mine's tucked up close like that too, but I haven't run it enough to know if its going to make a difference on the heat yet.

Also, if you don't need it, I'd take the torsion mount for that 221 off your hands when you are ready. Jeff.

[Dieselwrencher]

Yukonjack, I have had decent luck with sliding the engine and trans ahead one more bolt hole on the engine cross member, if yours are there, when putting a BBC in where the small block was. I did have one like yours that I had to cut a lot of the cab and a body lift it. I thought I was the only one that had that hinderence! LOL Good luck man. It's looking good though!

[Yukon Jack]

Jeff, I don't notice any heat on the cab floor from the exhaust, but there is quite a distance from the bottom of the floor to the top of the exhaust pipe.

In regards to the torsion mount, I think it is identical to the NP205 mount so I'll be using it.

A side note that I will mention, when I put the truck back together at the body shop I used new poly body mounts but for some really odd reason I found the body lift I used required me to cut I believe a full inch off the front radiator body lift puck. I never could figure out why all the pucks wouldn't need to be the same height.

Anyone have some insight on that?

[red71cheyenne]

Whoa, I'd really be interested to know if they are the same. I'd feel like a dumba$$ then, but that would be good to know. I thought they were different.

Oh, ya, I guess you would have alot of difference between the floor and the pipes with all that lift on there. I had to shave my core support pucks as well. About half as much as the regular cab mounts. Thanks, Jeff.

[Yukon Jack]

Originally Posted by red71cheyenne

I had to shave my core support pucks as well. About half as much as the regular cab mounts. Thanks, Jeff.

I have a set of the NP205 brackets that I haven't installed on my K5 yet, I'll try to remember to compare them next time I am in the shop so you know for sure. From the old posts I have read about swapping the T221 to NP205, no one has mentioned having to get different side mounts.

So did you have the poly cab mounts that you had to cut down? If so, that is very interesting - can't imagine why they would be selling something that was not the correct size. Very interesting.

[red71cheyenne]

Nah, this was the regular replacement cab mounts from Kenny's Trucks. It may just have been the issue's I was having getting the body lined up, but that was what it took to get the front end in the right place with everything else.

Thanks for keeping the eye out on the mount. 205 one's seem to be plentiful, so if it'll work, I'll get one of those.

[Yukon Jack]

Just ran out to the shop and confirmed the Rockwell's side mount is identical to an NP205's side mount.

[red71cheyenne]

Thanks for looking Yukon. Now, I'll just look for one of either. Jeff.

[Yukon Jack]

Guys, I woke up early again today and hit the shop with grand visions of progress. Did get a bit done but came to the conclusion that I'm probably not going to be able to ditch the body lift after all. After getting the engine centered up and looking at the frame and firewall issue it's looking pretty impossible.

The motor is going to have to move forward more than 3" to fix my firewall clearance issue. Moving the motor forward 3" will put the clutch fan within 1/4" of the radiator. Looks like I have a long water pump but I'm thinking switching to a short water pump and then finding all the necessary pulley's would be a major pain - I'm not even sure I could find the right pulleys since the motor and accessories are all 1989 vintage.

Plus, if I did get the engine forward 3" I'm afraid the frame would take alot of clearancing to clear the headers. Probably would need to cut between 3/8" and 1/2" to get them to clear. Using stock manifolds won't work as the stock pair I had originally would have taken major clearancing to work even in the present location.

Finally, moving the motor forward 3" or more would make the front driveshaft angle terrible.

I'd also have cut out and replace my exhaust under the cab and change back from a low hump to a high hump and also replace the basically new carpet with a high hump carpet.

All those things just add up to me thinking I need to just forget about removing the body lift - If I do that I can just get the transfer case replaced and get back on the road.

If anyone has any suggestions or comments, I'm all ears, but pretty frustrated at this point.

[jeffspower]

I don't mind my 3" body lift. I know alot of people hate them, but it makes just about everything easier to work on. I think it keeps underhood temperatures lower also, as there is more room for heat to escape. Without a body lift, there isn't much room to breathe. I've felt a noticible difference in the cab too. And it made my Blazer tank install a no- chop affair.

If everything fits good as- is, and your headers clear fine where they are at, I'm voting leave it where it is. If the truck sits a little high for your liking, knock a little suspension lift out of it as I did mine.

[Yukon Jack]

Got a little free time this weekend so headed out from some shop time. Spent a little time doing a little extra clearancing on the passenger side frame as when I got the motor situated again after modifying the crossmember the passenger side header was a bit too close to the frame.

Ended up using a thin spacer between the engine crossmember and the motor mount pad to raise the motor up just slightly and then used a cutoff wheel to cut a little frame clearance for two tubes. Was a tight fit getting the cutoff wheel in there - but got it done.

Pics don't really show, but I've got good clearance now. Ignore the battery cable, it doesn't end up there once I get it buttoned up.

Passenger side -



Driver side -



Next I took care of moving the transfer case crossmember back 2". I went ahead and bolted on the adapter so I could get the placement correct.



The forward white mark shows the previous postion of the front bolt of the crossmember



I luckily had a long 3/8" drill bit so I could easily drill the new holes. It was an old bit and my Drill Doctor sure did a nice job sharpening it!

My next step will be temporarily positioning the NP205 so I can mark and drill the side bracket holes. The NP205 crossmember is a little deeper than the Rockwell T221 crossmember so I'm interested to see if I run in to any problems getting the side bracket in place.

[Yukon Jack]

Grrr, well, I guess I'll be heading to the exhaust shop when I'm done - transfer case was contacting the exhaust when I tried to temporarily install it.



Hopefully will get out again this evening and actually get the transfer case in position so I can check out the drive shaft issues and mark the holes for the t/c side mount.

My dog gets all excited when she sees me grab my brown work jeans in the evenings. She's a Boarder Collie and of course they are a herding dog. Well, I guess I'm the herd. Anytime I brake out an air tool and get near the truck, she starts running around me and the truck. Not for a couple seconds - I'm talking she'll do it for thirty minutes if that is how long I'm under the truck. We head in and she's usually worn out from all the running - what a dork!

[Yukon Jack]

Hey for those of you following this thread, I thought I would do you all a favor and offer you my special skill, cause that's the kind of guy I am.

So what is this special skill you might ask?

Well, I have found I am very good at locating the sharp pointed edge of crossmembers under your vehicle. Specifically, I've found I have a special skill that seems to draw my head to the pointed edge of crossmembers, or for that matter, about any sharp metal edge under a vehicle. I know I've found one when I get this pain in the top of my head and I yell "Ouch!" or something similar that I can't say on this board, cause you know, it's family oriented!

So if you are having trouble locating such an item, just give me a yell and I'll come and find them for you!

Hit one last night so hard I was very surprised I wasn't bleeding. I think I'm gonna have to start wearing a helmet, by gawd!

[scotto0609]

I too have that same skill but I do not have to be under a truck! My big fat bald head has contacted all kinds of sharp hurtful things over the years! I have taken to wearing at least a hat to at least keep the blood from running down my neck!

[Tynee]

You know how some guys on this board are prone to offering their dogs as trade bait on a truck? Don't do that with her, she's too pretty. You may find yourself heavy one truck, and lite one dog...

[Yukon Jack]

Don't worry, she's not going anywhere - she's my shop buddy after all!

Got the NP205 temporarily slid into position last night. I tell you, that motorcycle jack really makes that job easy. I got it lifted up to the right height, about 2" from sliding in then used two long bolts as guides through the adapter bolt holes and slid it right into place.



For some reason my existing t/c side mount needs a spacer about 3/8" thick between the bottom of the inside of the frame and the side mount rubber isolator mounts. I'm also going to put in a 3/8" spacer between the side of the t/c and the side mount to put the bottom holes of the side mount a little further into the frame. Right now the holes would need to be drilled pretty close to the edge of the frame - this will fix that issue.

My front driveshaft will of course need to be lengthened but I'm gonna wait to do that until I get to the point of installing the Dana 60. Right now the front driveshaft would need to be about 29" long.

The rear driveshaft will need to be about 62" long. It is presently a 2 piece driveshaft but I'm not sure I will leave it that way. As you can see in the next pic, the factory drop spacer that the carrier bearing affixed to is directly in the way of where the NP205 output places the rear driveshaft. Ignore that wire you see - I hooked it to the rear axle's yoke and to the t/c's yoke to get an idea of the driveshafts location.



The outputs of the NP205 and Rockwell T221 are in totally different locations, heightwise. I hope that removing the drop bracket will be all that is necessary, but eyeballing it, it looks like I might have to clearance the crossmember that the drop bracket attaches to so the driveshaft will fit. I'll have to break out the grinder and cut some rivets - that is always such a joy to do!

Didn't knock my head on any crossmembers last night, cuss at the truck or go in ticked off - so it was a good evening!

Oh, a while back a boardmember sold me a bolt that attaches the shifter to the adapter - anyone know where I put it in the shop - I can't find it

[milled]

Nice work yjack. Hey, where did you buy you're flatbed?

[Yukon Jack]

There was a place called Bradtech in Derby, Kansas that manufactured them. The would make any changes you wanted - in fact the guy who built mine said he was so thankful I wanted a few different things as he gets board making their standard bed. They went out of business a few years ago unfortunately.

[milled]

Yea, there isn't as many fb makers as in the past. The best deal I've found has been around the $1500 mark, for a c&m. 8.5'x6'
Are you going to use the carrier bearing with the 205 or a strait shaft?

[va_tlc]

man yukon, you sure do go in depth with the details and thats a great thing for this board bud.looks as if your doing it right, i enjoyed reading this. youll be saving someone alot of trouble down the road if there doing this switch. good luck and stay safe that thing is heavy as your very aware of.