1993 C1500 project: 4.3L to 7.4L swap > 454SS clone

[BigBlocksRule]

Wow, sounds like you've had more than your share of problems with the 9.5" semi-floater. I've had 3 trucks with 'em that I worked hard and have never experienced any of the situations you described. Maybe the drivers were revving 'em up before dropping 'em in gear or dropping the clutch???

And ZooMad, you ain't going to get any Ford 9" built that's 2 - 3 times the strength of a 9.5" semi floater for anywhere near $600. Biggest you can slip in with stock parts is 31 spline, the Chevy semi-floater has 33 splines and similar bearing support to the 9". Once you go aftermarket, the sky is the limit, just like the pricing. I've seen dozens of 9" rearends puke the pinion out the front, it takes a nodular center section and Daytona pinion support to help cure this problem, should take 750hp or so with that and aftermarket axles. Again, I've NEVER seen a 9.5" puke the pinion out the front or otherwise blown up from too much power. I know a couple of guys with 454SS trucks with turbos putting out close to 1000rwhp, all they've done is upgraded the carrier to a good posi/locker.
The 8.5" is another animal, I wouldn't run one in anything with power, period.

DirtyLarry, I'm not trying to talk you into running a 9.5" rearend...it's your money and in the end, you need to be comfortable with how you spend it.

[TonawandaKid]

10 Bolt will be fine till you start doin holeshots, lol
Its the 3500 that will take a crap first.
Steve

[Palf70Step]

This will be very interesting to watch.

[TonawandaKid]

Larry,
I have a 14 bolt SS rear I'll sell ya,
I really want to build this Dana 60 I have anyways
2wd squarebody housing ends and brakes, just need to have axles made and there like 350 for a set.

[DirtyLarry]

OMG! If I hear one more thing about a 14 bolt semi floater that someone is trying to sell me I am going to go internet postal! I don’t want one of those junk axles! If I had a 14 bolt semi floater I would sell it too.

[TonawandaKid]

Lmao

[BigBlocksRule]

Yeah, TonawandaKid, he's sticking with a 10-bolt one tire fryer.
Everybody knows they're a much stronger and better rearend than the 14-bolt SF.

DirtyLarry, not razzin' you, but you are the ONLY one I've ever heard with the problems you describe with 'em. Most folks use 'em as an upgrade and are very pleased...probably since most of 'em blew up 10-bolts with the factory gov-bomb.

[tattoed71]

larry hows progress lets see some pics cool build

[vector]

Any updates Larry?

[hopped up]

hahaha!! hey larry ive got a 14 bolt ill sell you! haha!! jk! it seems noone has read about how you said your 70 year old fil isnt a leadfoot at all. and isnt planning on drah racinh the truck.
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[DirtyLarry]

Originally Posted by hopped up

hahaha!! hey larry ive got a 14 bolt ill sell you! haha!! jk! it seems noone has read about how you said your 70 year old fil isnt a leadfoot at all. and isnt planning on drah racinh the truck.
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Parts are starting to pile up around here! Tear down should begin next weekend.

So I am at a crossroads with the radiator and fan shroud. I plan to go with a 34” wide V8 radiator and LMC shows that the upper and lower fan shroud on a 454SS is an exclusive part to the 454SS trucks where a ¾ ton with a 7.4L is different part number. Anybody know if a 3/4ton fan shroud will fit a 1500? Not sure what would be different?? Or the other option would be to use a 1500 series 5.7L radiator and fan shroud. Does anybody know if a 5.7L fan shroud will fit after a 7.4L is shoved into a ½ ton GMT400 truck? I will be running 1996-2000 L29 7.4L accessory brackets so they seem to stick out further than the older style serpentine brackets. I want this conversion to look as factory as possible although the brackets won’t be period correct.

[m00n1957]

here's my 89 clone(project). it was born with a 4.3 and 5 speed. got a turbo 400 when the 5 speed craps out, gonna detail engine bay when i put in my "closed chambered" 454, right now i have a set of 781's on it.

[DirtyLarry]

Thanks M00N1957 but that didn’t help me at all.

Anybody know if a 5.7L fan shroud will fit a swapped in 7.4L? Or will a ¾ ton 7.4L fan shroud fit a 1500 series truck? I guess I’ll have to hit my honey hold boneyard this week and grab both type of fan shrouds to see what works. The swap starts next weekend.

[TonawandaKid]

Larry,
The 3/4 ton rad and shroud will fit the 1500, make sure you get the top rad brackets from the 3/4 ton. I had to buy mine. I have a all alum rad I bought from radiatorexpress.com
If you need a shroud I have a decent one.

[DirtyLarry]

Thanks Tonawandakid!

I’m going to hit up my favorite boneyard this week as I know they have two early 90’s 2500 4x4’s with TBI 7.4L engines. I’ll grab the fan shroud and brackets from one of them. The part that was throwing me off is the LMC catalog lists the 454SS as having its own fan shroud making me wonder if the 2500 shroud would fit a 1500. It is looking like the 454SS truck had a 17” tall radiator instead of the 19” like the 2500 series trucks have??

Thanks again!

[BigBlocksRule]

Dirty Larry, have you considered swapping your vacuum boosted brakes for a hydroboost unit? Nothing will stop you faster, first time I hit the brakes in a truck with hydroboost I almost threw all three of us out the windshield!!! It's an easy swap, there's tons of '88 - '98 trucks with 'em.

[beamn7]

Larry, checked my stash today and I don't have the alt we talked about. All I got left is a 100 amper V drive pulley'd one I'm savin for my 85. Sorry hoser!

[DirtyLarry]

Sorry if I was short with you m00n1957. It is just that I requested information if a 5.7L fan shroud will fit after a 7.4L is shoved into a ½ ton GMT400 truck then I get a picture of truck with electric fans. My hackles have been up on this thread anyway since people keep repeatedly wanting to sell me stuff I don’t want or need for this project.

Originally Posted by BigBlocksRule

Dirty Larry, have you considered swapping your vacuum boosted brakes for a hydroboost unit? Nothing will stop you faster, first time I hit the brakes in a truck with hydroboost I almost threw all three of us out the windshield!!! It's an easy swap, there's tons of '88 - '98 trucks with 'em.

Nah, not on this project. I agree though, hydroboost works great! I swapped on hydroboost on my K10 which made a huge difference in braking power. I just don’t think this light little Sportside really needs the added boost.

Originally Posted by beamn7

Larry, checked my stash today and I don't have the alt we talked about. All I got left is a 100 amper V drive pulley'd one I'm savin for my 85. Sorry hoser!

Thanks for checking, eh…. hoser

[sean1969c10]

You have seemed to have had a lot of trouble with this thread. I for one am looking forward to some progress, I have looked at some of your other builds and I like the way you approach your projects.

[DirtyLarry]

Originally Posted by sean1969c10

You have seemed to have had a lot of trouble with this thread. I for one am looking forward to some progress, I have looked at some of your other builds and I like the way you approach your projects.

Yes, it seems that way so I decided not to post any updates until it was done. Well, she is 99% done!

4.3L on its way out.


4.3L next to the 7.4L.


4.3L mounts just before removing them


Isn’t this nice, engine mount nuts inside the boxed frame so the lower control arms must be removed in order to replace engine mounts.


What a hassle! I’ll stick with square body trucks thank you!


Ready for an engine












Taking a ride to the exhaust shop Wednesday


Duals + Flowmaster sans cat




Called a friend that owns an AC Delco repair center and got hooked up with a new Tach instrument cluster. Calibrated to the actual mileage to boot.


Old non-Tach cluster


New Tach cluster



Youtube test drive.

1993 C1500 4.3L to 7.4L conversion - YouTube

Got a few small things to dial inbefore it goes into the paint shop. The A/C line needs to be reworked in order to connect to the accumulator. Tried to use a 1996-2000 Accumulator but those hosers at GM changed the threads from the to 27MM in 1996 so no easy way other than cut the farrell at the compressor and run a new hose to the accumulator with new crimp clamps.

[beamn7]

Nice job hoser! Sure your FIL is going to be ecstatic!

[Zoomad75]

That's what I'm talking about. NICE! Looks better in person though. Gonna have to get over this weekend to check it out and go for a spin!

[sean1969c10]

Very Nice, Another clean build!!

[92GMCDriver]

Wow great job that engine bay looks extremely clean, exhaust sounds great too!!

[Jharris29]

Truck looks great!! Hey was wondering what kind of motor mounts did you buy and where did you get them? Im currently finishing my 454 i have for my 94 single cab shortbed gmc k1500 4x4 with a 4.3L 4l60e transmission. also did you have to change the computer and harness? im getting close to dropping it in, i just want to make sure i have everything thats needed.