#$%@! Bent Push Rods

[MusicMan70]

Anyone have a torque spec on the rocker arm bar bolts?

My manual says 20-25ftlbs for the rocker arm shaft bracket bolts.

[1976gmc20]

I don't remember the heads on my 305 v6 being that terrible heavy, but I was a lot younger back then and pretty damn strong (worked in the timber every day!). Also, I had pulled the head on my old 4-cylinder Cat and that thing was really heavy!

Neither do I remember torque specs or order. I suspect that I just guessed back then, and the engine ran fine for years afterward, pulling heavy loads of logs. Those v6 GMC engines are pretty simple and tough, so as long as you don't do anything too stupid then you can't really hurt them. Too much rpm can be bad news, though.

Did you pull the distributor to remove the heads ??? You don't have to, you know I never did.

[wcstory]

Originally Posted by MusicMan70

My manual says 20-25ftlbs for the rocker arm shaft bracket bolts.

That is one of the few times I've guessed correctly. I did 25 as a educated guess.

Thank you MM

[wcstory]

Last night I spray bombed the heads.

Made some good progress today.

Clean the head and deck surfaces, cleaned the gasket surfaces, Re-assembled the heads, cleaned & painted the galley cover, installed galley cover, heads in & torqued, rocker bar in & torqued.

That bolt on the firewall side of the passenger side head was a SOB to access with the torque wrench. Had to use the old bend bar torque wrench for that one.

As it got dark I painted the intake and water neck housing.

[wcstory]

Originally Posted by wcstory

What's not to love about a motor that you can put a quart can into the cylinder.

forgot to add picture

[wcstory]

Found it!!

[TJ's Chevy]

Cool stuff! Hey, the 478 had a 5.125 bore. lol!

[wcstory]

Got the rest of the top end assembled.

I pulled the spark plugs out and put marvel mystery oil in the cylinders before turning the engine to install new push rods and set the cold lash to .020.

A little gas in the carb and she fired up. Let her idle as I added the rest of the coolant and tightened leaks.

After she got good and hot I set the lash to .012 on intake and ,018 on exhaust valves. I need to grab a timing light and set the distributor properly. She still spits and sputters under load.

Wondering if I should just drop in the new HEI, kind of wanted to address one issue at a time.

[TJ's Chevy]

How was it? lol I disassembled and reassembled the top end of my 305 in one day....whew what a Loooooong day. lol Least your heads and covers don't have grease marks all over them like mine do! Spitting and sputtering under load sounds like a carb, timing, or vacuum problem.

[wcstory]

Originally Posted by TJ's Chevy

How was it? lol I disassembled and reassembled the top end of my 305 in one day....whew what a Loooooong day. lol Least your heads and covers don't have grease marks all over them like mine do! Spitting and sputtering under load sounds like a carb, timing, or vacuum problem.

If I wasn't trying to clean, wire brush and paint everything it would of taken a heck of a lot less time

Mechanically she seems fine, I think it's the carb and ignition I have to battle with next.

https://www.youtube.com/watch?v=PBLQRVSzU2U

[TJ's Chevy]

It won't let me see the video.

[wcstory]

Tried to embed video with no luck

[wcstory]

Well after all that work she still wasn't running worth a hoot above idle.

Started re-checking everything. Valves lashed properly, checked the carb for vacuum leaks checked the distributor cap & wires for good connections, checked the spark plug wires twice to make sure they were in the correct spot (I marked them where they came from) - see a flaw in my thinking

Yes folks I didn't check to see if the plug wires were in the RIGHT order before marking. 1 & 2 were flipped. DOH!!! Stupid human tricks again.

She still wouldn't stay running for more than a few seconds. Start tapping the gas tank....hollow, hollow, hollow.... You have to be kidding! Empty 5 gallon mower gas can into tank. WooHoo!! I twisted the distributor till it sounded decent and tightened it down. Hell with the timing light I was going for a ride!

It's amazing how much better they do when you use the factory firing order.

A few laps around the development weren't enough so I got adventurous and grabbed my wallet and cell phone. Drove all the way to the local gas station to put 10 gallons in and then back home....2.5 miles round trip, maybe 3 if you count the neighborhood victory lap, but it still felt good , damn good.

Manual steering, bias ply tires and 4 something gears definitely made her feel like a truck.

Now I'm even more impressed! Cylinders 1, 3 and 4 had stuck valves or popped push rods - 0 compression. Cylinder 2 had the wrong plug wire. So she was running on 2.5 cylinders. That's impressive.

[TJ's Chevy]

Don't underestimate a GMC V6. lol

[wcstory]

Originally Posted by TJ's Chevy

Don't underestimate a GMC V6. lol

And don't underestimate the online community.

Thank you