'66 GMC BBW w/351E and Factory Buckets

[y5mgisi]

Hey you guys are on pirate also! Really liking this build!

[66-PMD-GMC]

Very nice find on the truck. The Holley IMO is too much carb for the V6 but of course the Holley lovers on the GMC site will fight me to the death on that one. I had a reparable carb guy do my Rochester for the V6 that was in my GMC and it was the sweetest running motor.
That auto transmission option on the V6 is as rare as hens teeth BTW

[Corts60]

Originally Posted by 66-PMD-GMC

Very nice find on the truck. The Holley IMO is too much carb for the V6 but of course the Holley lovers on the GMC site will fight me to the death on that one. I had a reparable carb guy do my Rochester for the V6 that was in my GMC and it was the sweetest running motor.
That auto transmission option on the V6 is as rare as hens teeth BTW

Actually, that carb isn't too far off if you use the calculator:

http://www.gtsparkplugs.com/CarbCFMCalc.html

If you do the math for a stock application, you get 366 CFM required. If you choose modified, you get 448 CFM required. These calculations are with 3600 RPM redline (V6) and volumetric efficiency of 1.

[RockTonka]

Originally Posted by y5mgisi

Hey you guys are on pirate also! Really liking this build!

Yep, found our way here from Pirates...don't hold it against us though

We're hopeful that we can tune the 500 to run on the 351...they're doing it on the 305's, and the HEI should help.

[66-PMD-GMC]

Originally Posted by Corts60

Actually, that carb isn't too far off if you use the calculator:

http://www.gtsparkplugs.com/CarbCFMCalc.html

If you do the math for a stock application, you get 366 CFM required. If you choose modified, you get 448 CFM required. These calculations are with 3600 RPM redline (V6) and volumetric efficiency of 1.

Yep, and that shows the Rochester as the better choice but it really doesn't matter. Fact is there is an original V6 between the frame rails and a Chevy isn't desecrating the engine bay LOL
Whatever you boys choose, best of luck to you and have fun with it. That in the end is what really counts

[duallyjams]

If you have a stock carb that is in good shape then yea its great but if the shafts are wore out and is not repairable the 500 will work as a replacement.

[66-PMD-GMC]

Originally Posted by duallyjams

If you have a stock carb that is in good shape then yea its great but if the shafts are wore out and is not repairable the 500 will work as a replacement.

There is a carb shop here in Phoenix that has 2 bbl Rochester carbs for about $150 exchange. Mine is off a/or for a 65 chevy 327. Bushed shafts and set up to bolt on and go. That's just an option that is available.
My beef with the Holley?
1 back fire and there goes the power valve. Every fricking time.....
Just a personal observation.

[RockTonka]

Originally Posted by 65GMCFirstride

wow thats in greaat shape is that chrome grill orianal

I think so...

[Captainfab]

The newer Holley's have a power valve protection to prevent such problems. You can also install a similar device in the older Holley's.

Originally Posted by 66-PMD-GMC

There is a carb shop here in Phoenix that has 2 bbl Rochester carbs for about $150 exchange. Mine is off a/or for a 65 chevy 327. Bushed shafts and set up to bolt on and go. That's just an option that is available.
My beef with the Holley?
1 back fire and there goes the power valve. Every fricking time.....
Just a personal observation.

[RockTonka]

We decided to fool around with the Holley 500 simply because of finding one on the cheap. We did have the Rochester rebuilt, but it still seems to leak a bit around the throttle shaft and base, prompting us to experiment a bit.

Ignition concerns drove the decision to convert to an HEI set-up. Sourced a Buick even-fire HEI from Jeg's along with some generic wires and a bushing adapter as referenced here...http://www.6066gmcguy.org/hei.htm.

The new set-up dwarfs the old points dist., but it fits. We swapped the old drive gear onto the HEI and....







I know that I'll eventually regret this, but...








I welded the drive gear to the new dist. instead of drilling and roll pinning


It seemed to make enough sense at the time.


The larger cap is a close fit here and there...but will just clear both the firewall and throttle linkage (thought we'd have to remove that).

We may drop the old Rochester back on for a bit and time it... one thing a time!

[66-PMD-GMC]

You can also pop a TBI 2 BBL EFI unit on that V6 if funds ever permit. They are IMO the hot new mod to any motor.

[Andyboy]

just seen this thread, just wanted to say great score.

[jbclassix]

what kind of transmissions can you run behind the GMC V6's and V12's? Do they have the chevy bell housing pattern or is it different?

[duallyjams]

Originally Posted by jbclassix

what kind of transmissions can you run behind the GMC V6's and V12's? Do they have the chevy bell housing pattern or is it different?

The bolt pattern is different but they made adapters for the automatic trans for the power glide and turbo 400.

[283nova]

my friend has those seats in his dodge truck, buddy-bench

[RockTonka]

We dropped the Rochester back on and rolled the dist. in by ear...starts, runs, and stops MUCH better. Actually laid a bit of rubber down going around the corner of the neighborhood . Gonna try and play with the Holley this next week.

[RockTonka]

[RockTonka]

My son's been working on little things when he can. Pulled the side mirrors off and replaced with a repo round one, got some new armrests and visors, got the seatbelts cleaned up, and cleaned up some more of the shiny parts.

[RockTonka]

Well...


That Holley we've been chasing turned out to not be the #4412 Holley 500 we wanted. Working with a friend that had what he thought was a 500 off of a boat and bought it sight unseen. My son picked it up today and looks like we have a 300 or so 2-barrel Holley...I need to do some more research.

But, it was freshly rebuilt so...

We went ahead and modified a #1937 Holley to Rochester adapter to work with the 351E's larger intake pattern and dropped the carb on.

Everything hooked up cleanly and other than a non-functioning electric choke, actually ran pretty well for not being dialed in...easily better than the Rochester. We'll tune it a bit over the weekend and decide if we still need the 500.

The chrome will go away when we have time to find something more appropriate.

[duallyjams]

All you need now is some plaid valve covers.

[RockTonka]

Originally Posted by duallyjams

All you need now is some plaid valve covers.

I wouldn't pass a set up!


Took the truck over to a buddy's shop to get it up on the lift and work through some of the leaks. The master was flowing pretty good, and we have leaks from the power steering, valve covers, and tranny pan.
Pulled the inspection cover...pump/front seals and rear main seals were good...new filter, gasket, and fluid and the tranny is good to go.
New valve cover gaskets and a master took care of the biggest leaks.
Asked a mechanic buddy to drop by and help with giving it a good once over...pleasantly surprised to not find any surprises. Everything looks pretty solid.

[duallyjams]

The inner fender is a built in work bench witch makes it nice because nothing rolls away.

[RockTonka]

Originally Posted by duallyjams

The inner fender is a built in work bench witch makes it nice because nothing rolls away.

That's the truth...plenty of space to stack crap! Nothing rolled away, but a 9/16 wrench managed to walk away.
It'll probably show up in a frame rail or something.

Well, we decided to go ahead and bring in a new 4412 Holley and I'm glad we did!! It really runs much better than either the Rochester or the 300/350? Holley we had to play with.
Set the initial timing to 5 UTC and tweaked the carb just a bit from factory settings...seems alright for now.
We are thinking about a couple 2.5" 50 series dumping in front of the rear tires out of some 3" slash cuts

[oklahomaduner]

Well we have been slacking on getting stuff done lately, but we did manage to pick up some slack and get a little bit done.

I pulled the tank awhile back and tried cleaning it out... but I didn't do it good enough. Junk was still showing up in the gas. So i decided to go through the whole process of cleaning and coating using Bill Hirsch's kit. It was surprisingly easy to do so we'll see how it holds up

We also had been keeping our eyes out for a new rear end since the 5-lug, 2.73 geared axle wasn't working for us. After stumbling through all the local salvage yards, we ran across a never-installed rear end out of a 2007 colorado. It has a limited slip, 3.42 gears, and its narrow enough to run some fat rears later on. But for now some 2" spacers made the ralleys fit perfectly!

After all that was done we ran it to a local muffler shop and threw on some dual magnaflow's with 2.5" pipes and 3" chrome 45 degree tips.

[67chevy1series]

when you dumped muratic acid in did you line it right after or did you just put gas in it?