Re: My 78 K15 High Sierra build - Fish Tremble
 

I was just looking in the LMC catalog and remembered I also used the metal foil sound control mat that they sell. I put that under the padding.

Re: My 78 K15 High Sierra build - Fish Tremble
 

Thanks for the info Greenlee. I've already got sound deadener and a closed-cell foam insulation on the floor. Adding the padding/jute would mainly just to help deal with heat and noise from the firewall and transmission hump. More has got to be better, right?

Re: My 78 K15 High Sierra build - Fish Tremble
 

Had all the kids home for the holiday weekend, but still made some pretty good progress to get Hazel back on the road over the last couple weekends.

Got the tranny hump patched, re-undercoated, insulated and installed. Also got the vinyl flooring installed and the rest of the interior put back together. I got the front step-bar mounting bracket refabricated for the driver (important) side but still working on the passenger side. I still need to fix the drain for the AC condensation and get my driveshafts rebuilt and balanced. Otherwise pretty much done with this "mini" project.

While the truck has been down, my registration expired. Where has the time gone? I can hardly believe that it has been a year already that the truck was done enough I felt it needed to be legal out on the roads!

Re: My 78 K15 High Sierra build - Fish Tremble
 

Time flies!

Re: My 78 K15 High Sierra build - Fish Tremble
 

Got my rear driveshaft back from the drivetrain shop yesterday and mounted it up. Length was still fine and nothing needed replaced/rebuilt but it turns out that it was quite a bit out of balance. Man what a HUGE difference that has made. I guess that the moral here that I shouldn't have assumed that any original parts were good as-is just because they looked good. There are already enough issues to chase down after assembly is complete.

Looks like because of the angle I'm going to have to swap out the front yoke (or whatever it is called) on the transfer case to use the double u-joint style shaft. Wish I'd done that when I had the TC out on the floor. Project for another weekend...

Re: My 78 K15 High Sierra build - Fish Tremble
 

Well crap, if I had noticed the single yoke in a pic you posted I may have spoke up cause the NP205 has a double Cv type joint. Now if you do that your going to have to shorten the shaft length. Trying to install the shaft with the CV joint is a bear too! Least on my truck

Re: My 78 K15 High Sierra build - Fish Tremble
 

Yea, I got myself into a bit of a mess using this NP205 I just installed. It's a bit older NP205 that came out of a donor '76 Blazer and the front output has a yoke for a 1310 (I believe) u-joint. The NP205 I just pulled out was the one that came in my '78 and it has a front output that is a flat plate with 4 bolt holes that a CV type joint connects to. This weekend I looked into just swapping between the NP205's but the currently installed is 10 spline and the other is 30 spline so no-go.

Looks like the '76 blazer would have come with a CV style joint as well, but the rearmost u-joint just goes into the yoke on the TC rather than terminating in a round flat bracket that bolts to the flat plate style TC "yoke". Not sure if that made sense. And it looks like that shaft may have to be cut shorter.

So, looks like I could go that route, or else swap my original NP205 back in. Not sure I can do that either because the input has to match the AA adapter coupler, but haven't looked into it yet.

Re: My 78 K15 High Sierra build - Fish Tremble
 

\


Yea you made sense, my trucks front shaft has the round plate the 4 bolts go through, but I admit I don't know what the yoke is called it bolted too so I'll take your "TC Yoke" as the word.


Yea the joys of custom builds, hope you can verify the input shafts before you can go any further!

Re: My 78 K15 High Sierra build - Fish Tremble
 

Wow, hadn't realized how much time has passed since I updated this build. I did manage to get my 4wd working again. On the transfer case issues, I had to stick with the case in the truck because that had the input that would work with the Advanced Adapter coupler to the NV4500. What I ended up doing was swapping the front output from my original TC into this one. Put together a front driveshaft from parts of a few I had stashed. Good to go!

Since then, I've been driving daily and she's done pretty well. Took her on the first long roadtrip, maybe 2 hours away, to visit my daughter's new place. Handled pretty well up to 75MPH but there are a few things I need to address. 1) The NV4500 howls in 5th gear. Not typically a problem because I rarely get above 4th for day to day driving. 2) Have wind noise pretty bad above 60MPH on driver side. 3) I love the sound of my exhaust, but blasting down the highway for a couple hours it gets really old not being able to hear the radio or talk with a passenger. I need to find mufflers that sound aggressive when I put my foot into it, rumble nicely at idle, but are relatively quiet when i'm cruising giving just enough pedal to maintain speed.

Hazel did get a Christmas present I've just finished installing. Got vacuum and AFR guages. Now I'll be tweaking the tune for a while.

Re: My 78 K15 High Sierra build - Fish Tremble
 

Nice to hear how things are going, I must agree on the exhaust note, it sounds good for a bit but long hauls take their toll, my little Dakota I did a dual in/out Flowmaster 70 series, it still resonated pretty bad so I had the shop add 2 magnaflow mufflers in front of the 70 series. Crazy as it sounds it actually sounds really nice. My Rat got 2 18” magnaflows which were discontinued and it is perfect for me.

Re: My 78 K15 High Sierra build - Fish Tremble
 

Get a quiet muffler and electronic cut outs. That’s what we have on my dads 68 BBC Camaro. It works well.

Re: My 78 K15 High Sierra build - Fish Tremble
 

Nice! Pumped you have been driving the wheels off of it. My big truck has 3.5” magnaflow with a cat in front and it is very livable. Still pretty loud when you let the horses run of course...

Re: My 78 K15 High Sierra build - Fish Tremble
 

Glad to see you guys still keeping an eye on this.

The mufflers I currently have are Magnaflow 13215XL which have a 14" body. I had to get a new piece of exhaust pipe bent up to go around my new setup for the transfer case and dual sticks and the guy that owned the shop said that if I like the sound but want it quieter at cruise, get a longer or bigger bodied muffler. This morning I ordered a pair of Magnaflow 13255 mufflers which have an 18" body, so they are still available Mike.

I think for the wind noise I'll get some of the seals that mount to the door around the window and see if they help. The truck had some originally but I didn't replace them after paint.

As for the 5th gear howl, I've been debating a different oil. I used Amsoil which says its for the NV4500, but it isn't the OE specified oil. The right oil and additives made a big difference in the rear end. Just hate to drop the $$$ not knowing it will help. But then again, I don't know of a shop I trust to go through the NV4500 again and hate the idea of pulling it back out of the truck again. Marcus I hope your tranny is still behaving itself. I know how it is to pay for a rebuild and then discover you might not have gotten what you paid for like your previous rebuild.

Boynton, still waiting to see a thread start for the Blazer, and are you getting any sleep yet? Mike, it won't be long till the weather makes you want to get yours out and work on it again.

Re: My 78 K15 High Sierra build - Fish Tremble
 

Glad to see Hazel is still on the road and getting the kinks worked out! I got really lucky with my vent windows. Me and a buddy had bought a 91’ Suburban for parts. He was building a K5 at the same time I was rebuilding my truck. We had just about used everything we wanted and were about to take the remains to the scrap yard when I noticed the vent windows looked really good, so I snagged them. They don’t have any wind noise at all. I later read on here something about those later model Suburbans having a different design??? All I know, is I’ve had plenty of them on old trucks in the past that had wind noise!

Re: My 78 K15 High Sierra build - Fish Tremble
 

Hi Greenlee, I did rebuild my vents with new rubber. At this point, I'm not sure if the wind noise is from the vent or the front edge of the door. I've already "adjusted" the front window frame with wood blocks and heavy shoves. I'm thinking the extra weatherstrip can't hurt and should be a fairly easy upgrade.

Thing is, now that the truck is my daily and not my main project, things like this just have to be added to the list. If it bugs me enough, it moves up in priority:lol:

Re: My 78 K15 High Sierra build - Fish Tremble
 

Hey there Rick, hows it going. Those seals that go above the door sash, should help with the wind noise.

Re: My 78 K15 High Sierra build - Fish Tremble
 

Hi TKCR, doing just fine on this end. Hope you are as well. Sounds like your retirement is coming right up, I bet that you are excited.

In fact, I just got on to try to find the old thread about these seals and the adhesive to put them on.

Re: My 78 K15 High Sierra build - Fish Tremble
 

Yep I have 7 more working days. March 1st is the official day!,
Here you go. The adhesive and then the how to video.
https://shop.advanceautoparts.com/p/...8008/7720004-p
https://youtu.be/qDBojIza-TA

Re: My 78 K15 High Sierra build - Fish Tremble
 

Thanks much! I was still hunting for that thread. I thought I'd subscribed but I guess that I wasn't that thoughtful.

Re: My 78 K15 High Sierra build - Fish Tremble
 

Good luck, I never put mine on. Never really needed to, after replacing all the door seals and rebuilding the vent windows.

Re: My 78 K15 High Sierra build - Fish Tremble
 

You have really been getting things sorted, how many miles have you put on Hazel now? I'm guessing that the 5spd is pretty nice! :mm:

Re: My 78 K15 High Sierra build - Fish Tremble
 

Hey Brett, good to hear from you. I think I have about 6000 on the odometer, and maybe another 1000-1500 before I got the odometer working.

Funny you should bring up the 5 speed. I am going to be picking the truck up from a transmission shop a little later today. It's been there since a week ago Monday. I've had a really annoying loud whine and rattling whenever I put it into 5th gear. Doesn't appear to have anything to do with the truck's speed or RPMs, just happens anytime and the whole time it is in 5th. The transmission is great 1st-4th and reverse. I spent some time checking around and found this shop in the area where the guy has been building transmissions for going on 40 years. Everyone brings their manual transmissions to him because he's one of the only shops around that will work on them.

He test drove, heard the racket and figured it would be easy to spot the problem. He found a couple bearings that didn't look new, but not too bad. The rest appeared to be new (I'd had the NV4500 rebuilt about 6 years ago and never used it until now). Found nothing he was confident was causing the noise. No metal scraps in the oil, nothing. I had him replace those "suspect" bearings since I was already paying for all the labor.

Well, the noise didn't go away. He can't figure out where its coming from. Suggested I just drive it since it doesn't look like anything is being damaged. Maybe wrap it with more insulation. Grrrrrr..... Fortunately, most of my daily driving doesn't get out of 4th anyway.

Re: My 78 K15 High Sierra build - Fish Tremble
 

Yay, I have my truck back. The transmission shop cut me some slack and only charged half the labor, which put me at about $500 less than what I was originally quoted. I didn't even have to ask, the invoice was already written up with the discount. Tom, the owner, was the guy doing the work and he'd been up-front all along about what he was or wasn't finding wrong. I'd use his shop again. It might be wishful thinking, but 5th gear might be at least a little quieter than it was.

Re: My 78 K15 High Sierra build - Fish Tremble
 

Not much to update on this truck. Couple little upgrades like real fog lamps up front and finally got windshield washer pump to work. Almost 9000 miles of daily driving.

But, I have a new toy to play with on my weekends. 71 GMC 3/4 ton LWB, 350, TH400, maybe 3.73 gears. SPID looks really clean so wondering if it is a reproduction, but presumably this was a big block truck. May have to put it back to that. I see signs of rust repair and a few small bubbles under the paint, but this truck is 98% more rust free than what I started with on the '78. Also quite obvious that PO(s) have spent a fair amount on this already as the interior is mostly new. I have no plans for any near term project to finish the restoration. Just plan to finish getting it mechanically sound and use it. Well, actually it may be the wife doing more of the using it :lol:

Re: My 78 K15 High Sierra build - Fish Tremble
 

good looking "new toy" ya got..!!!