79' GMC C15 - Spruce Caboose

[bix]

well ive been tinkering 10 moinutes at a time for most of the past while but my mom did come and meet her grandson, which gave me some time to button up a few things. The nice weather is here and i wanna get this thing runnin!



I picked up a double roller set off a buddy of mine, and im happy i did because i must have messed up installing the cam gear last time, since i had about 3 times the allowable endplay.. I dont think i realized how it takes some patience to set the gear fully on the cam snout. there was some wear on the retainer plate from the chain having room to move around i think.. I also reused the original retainer plate last time and the gasket was cooked flat. Two of the countersunk torx screws were tighter than my pants when i saw my first squarebody..so I welded two 5/8 nuts on them and got em out easy enough. I opted for bolts in place of the countersunk torx screws when i installed the new retainer plate.

The double roller set is a comp cams setup with an adjustable crank sprocket for advancing or retarding timing. I put it at the 0* factory setting. Comp says that no chain dampener is needed with this timing set, but i did have this more simple GM one laying around ( new ) and put it in there anyway. The factory one was orange and definitely had wear on it.

The cam gear came with a nice thrust bearing installed on the backside, and got some ARP cam gear bolts. Pulled the old crank sprocket and got the new one installed, cam gear and chain installed. I did pull the cam and everything seemed ok, so back in she went with some lube.. found some minor lateral marks from it being able to move front to back? ( too much end play ) I ignored the cam bearings and just moved forward even though they were showing some signs of wear.. despite me wanting to dial bore them, but without money to replace em i figured they were probably alright. And If i have to dive into this thing later on, i just want it to be in the truck so im moving forward with progress right now regardless.




I soaked a few rags in water and then placed them all around the retainer plate when i welded the nuts on.



















The timing set came with two spacers for the factory oil pump. Drivers side is tricky because the spacer can fit both orientations but one way will restrict the oil flow galley so be careful to make sure its installed the correct way. I thought i was all good to go and then realized id have to modify the timing cover. I had to take the corner radius off the bulk of where the cam sensor bolt is seated to get clearance for the chain. I also then realized the two block mounting bolts for the oil pump on the drivers side hit the timing cover now too.

Instead of modifying the cover more i figured id see how much the bolt heads were hitting. I put some lube on the bolt head and installed the cover. Once i verified it was only the two bolt heads were touching, i took off about half with the bench grinder and checked again.. Clearance issues solved!














Also got the old seam sealer all scrapped off the firewall, re sealed with new seam sealer, primed and painted for now. I still have a section under the pass floor side but now atleast i can stove this driveline back in here.

 

[Fastereddie]

The cam gear/chain doesn’t hit the retainer plate bolt heads? I thought they had to be flush for clearance. And don’t you lose the locating effect of the countersink bolts? Maybe I read it wrong?

 

[bix]

Then it was on to the valvetrain... I had noticed quite a bit of movement in the trunnion bearings on the stock rocker arms. No specs on how much play there should be and with some worse than others i figured itd be worth it to get new pushrods and rocker arms. I just went with Melling replacements off rock auto. The bearings are captive with snap rings which is nice and they are way tighter than the OE ones that were on there. Pushrods are stock length chromoly replacements. I believe they are stock thickness also even though i was hoping to get some thicker ones.

One of the old rockers had some scuffing around the curved base that sits in the rocker shaft seat. I may have torqued one down while it wasnt fully on the base circle of the cam...? either way its replaced now. I torqued them down to 22' lb one by one while turning the motor over to get the lifter on the base circle. Went over again and checked torque. Will also go over once more before fire up or shortly after n triple check.

The old balancer had a bunch of decent cracks in the rubber elastomer thats seated in it, so i grabbed a new GM unit. I read that the crank snout shouldnt be recessed more than .175 " passed the innermost ridge of the balancer. I have a uniform .110 around so ill call that good. I still havent torqued down the new Balancer bolt at all as i cant find my 1 1/16 12 pt socket...

Got new seals on the valve covers for the mounting bolts and new valve cover gaskets as the older ones didnt fit well and i had cut n glued them inplace.






























I also drilled some extra holes in the baffles with no actual research so i hope that helps...?

 

[bix]

The cam gear/chain doesn’t hit the retainer plate bolt heads? I thought they had to be flush for clearance. And don’t you lose the locating effect of the countersink bolts? Maybe I read it wrong?

I did have a mini jammer when i thought that would be the case, but turns over just fine. I just eyeballed it around the cam when tightening the 4 bolts. I guess i could have bent some feeler gauges and made sure it was centred, but i figured all that had to line up was the gasket around the oil path really..and the bearing locates the cam lobe within the bore, and the retainer is basically a fancy cam button...? but i just assumed all that.

 

[Chevy305]

Nice progress

 

[bix]

Nice progress

Thanks, its all about consistency at this point, even if its a couple bolts a day.

 

[bix]

I managed to get the water pump bolted on and new thermostat in. I was thinking it was sure nice of them to include two new housing bolts.. then the two OE ones snapped... and it all made sense. the tensioner is pretty shakey so i may get a new one but ill see how this one does if i pump some grease in the bearing.

I also put the intake on so i could the lines for the steam ports. It seems the gen 3 ls engines had the 4 hooked up from factory and the gen4 models only had the two front ports connected and no TB line either. i read it was because with the 4-5* angle of the engine , any air pockets would go to the front two? I figured having 4 and needing 2, seems better than having 2 and needing 4..

 

[folkenheath]

I also drilled some extra holes in the baffles with no actual research so i hope that helps...?


View attachment 446684

Nice work overall on your build keeping things clean.

Check to make sure those holes aren't directly above the rocker arms, as that may cause you to get oil mist out your system.

 

[bix]

Nice work overall on your build keeping things clean.

Check to make sure those holes aren't directly above the rocker arms, as that may cause you to get oil mist out your system.

Yea I’ll check and maybe plug aome if that ends up being the case, thanks! Would have never thought about that

 

[bix]

Also I’ve stared at this too many times and thought to post it on here.. Figured it could help some people like it did for me, to stop looking up crap all the time in my phone .

 

[Chickntrk]

I love the patina on the rocker covers

 

[bix]

I love the patina on the rocker covers

Rattle can paint on un prepped aluminum can mimic 60 years of sun aging in just one year

I ran a little Richard scraper down them and just got any bubbling off and anything that came off easily went too. Then I went 180 grit by hand and then 220.

 

[76zimmer]

Use zinc primer on bare aluminum!

 

[bix]

It’s better to dream with parts...



AWD components from an 03 denali. Lucked out due to junkyard prices ,but also because apparently after 2007 Gm's AWD system got worse from what ive read... Will be fun to dream up what it would take to make this truck AWD.. until the reality of what itll take is right infront of me.. then it may become a nightmare, but until then ....

 

[Chevy305]

Well that escalated quickly

 

[bix]

Well that escalated quickly

it always does...... but i just stumbled across these on marketplace for 50 bucks so i couldnt say no . Its a long ways away but no point walking past parts you know youll want one day. Itll put some size references to the parts involved so i can actually see what the hell itll take to stuff this up under there. Obviously the trucks were built to house a Tcase so thatll be no issue, but the front drive and suspension is where itll get interesting.

 

[bix]

Put in a late night shift last night...

Got the ARP crank bolt torqued to 235' lb and got the torque converter stabbed onto the transmission and verified that it is seated fully. I am getting 26.5mm / 1.050** from mounting surface on torque converter to mounting face of transmission and block. The flextplate is about 22.5mm/.825* off the back of the block which leaves me 4 mm roughly. I have to double check but i think thats a good amount of room for things to grow id say. Seems the two square cut outs at the end of the stator(?) on the torque converter which engage the pump, could be out or in 3-6 mm without any point loading near one of the edges, which seems to be a common issue with not getting the converter seated properly inside before bolting to the engine and destroying the pump engagement and then the transmission to follow since it has low oil.

 

[bix]

Got the engine and trans in the truck with the engine mounts moved forward, which definitely made it a pain in the ass and i lost all my room for sctivities , but the good part is that the transmission xmember should be back to stock location and my driveshaft should be back in the fun zone. I also almost forgot to get the servo pin shaved down a bit before installing, so i managed to do that before i put the drivetrain in.

I had to take about .010-.015 off the end so it didnt take too long to do. I used 220 grit sandpaper, then 400, then 1000 grit with a feeler gauge of .020, for a reference on how much would have to come off. I ended up getting .090 of travel in the pin and sonnax refers to needing .075-.125". I have ZERO idea or memories about what this threaded hole is on the side of the tranmission, but dang wouldnt ya know the post for my dial indicator threads right in there... Ill assume thats my win for the year, and ill soak it in Lol.




































































































it fought me all the way for some reason.. maybe a one man show isn’t too productive after all.. I ended up with a 6* crank angle which isn’t ideal as from what I’ve read should aim for over 3 and under 5 for drivelines? Im tempted to swap the motor mounts to get some more angle and create a little more room under thetrans tunnel, but I don’t want to do it unless it’ll be worth it to just do it now while it’s a lot easier…

 

[folkenheath]

Most factory GM angles are 4 degrees I believe, but you could easily just move your pinion angle to match on a 2WD and it wouldn't matter that much. Also, did that account for the current angle of the truck? Was the front end up for the install? It will definitely drop down a little when you put all the weights and fluids back in/on the front.

Also, I've had the indicator rod thread in the part a couple times over the years too, you feel so lucky when its aluminum and you can't use the magnet!

 

[bix]

Most factory GM angles are 4 degrees I believe, but you could easily just move your pinion angle to match on a 2WD and it wouldn't matter that much. Also, did that account for the current angle of the truck? Was the front end up for the install? It will definitely drop down a little when you put all the weights and fluids back in/on the front.

Also, I've had the indicator rod thread in the part a couple times over the years too, you feel so lucky when its aluminum and you can't use the magnet!

right on , thanks for that, ill leave it alone for now because I’d rather not go down that road for now. The mounts measure 4 inches or so off the crossmemeber and I don’t think I’d gain all that much from aftermarket mounts for all the work it would take. I was thinking about clocking my pinion angle to match. Anyhow. As for the truck it’s sitting on its own weight on 4 dollies so it should simulate ride height but here is still all the front body panels and fluids to add weight so you’re right , it will probably sink down a tad. As long as I can match the angle for the driveshaft I guess it’s a moot point

Hoping to move the x member and get the trans finalized this week, I may skip the shifter install for now and see how much time I have once it’s closer to driving and just tackle that as it’s own project. Really just wanna see if this transmission even works