The distributor is a reman. that I installed when I switched to DS2. This is a few years ago but probably less than 10K miles. From some of the comments I have heard about reman. parts, who knows what it could look like inside. Another good reason to pull the distributor and check it out.
I can try disconnecting the vacuum advance and testing before I dive in too deep..

 

That would be an easy test.

 

This probably won't be your problem, but it could help. Your carb is under jetted. An under jetted carb will cause excessive heat and low power.

A stock 302 from back in the day came with .52 -.54 jets. Using a calculation of jet size per cubic inch, a 351 should use .59 - .62. I didn't go into all the numbers used to come to that , but I would go with the .59 jets you have if the bore of the cylinders and most everything else is stock, .62 if things are above stock.

 

I am back with some good news (at least for now). My problem seems to have been rectified.

For those not wanting to read through 9 pages of thread to reconstruct, I was having a stumbling/bucking on hard acceleration under load (read that as steep uphill) on the truck in my signature. Suggestions ranged from fuel issues to electrical, with many parts being checked and a few replaced to no avail.

In the midst of this I had switched from 53 jets to 55 jets and checked the power valve, which needed the gasket surface cleaned up. The gasket also didn't look like the normal Holley round PV gasket, but more like a triangle that had been over-inflated. What idiot put that gasket on there? Oh yeah, me. So I picked up some Holley PV gaskets.

After pondering Yardbird's suggestion (above) for a while, I decided to go up in jet size to 57 and change the PV gasket. I figured I could always go up to 59 jets if I saw an improvement. I drove the truck for a week or 2, and have noticed an significant improvement in uphill acceleration without issues and an increase in fuel mileage of 2 MPG, which on this 4x4 is a nice percentage jump.

I don't know whether it was the PV gasket change or the jet increase or a combination of both that did it. I know better than to make 2 changes at once but I have been so frustrated with everything that was tried and failed to solve this problem that I kind of assumed neither change would fix any thing.

I intend to install 59 jets and test some more. If that works, then I will have the equivalent of the Canadian non-EGR carb (59 jets /6.5 PV). I will be eventually switching to an Edelbrock 1406 4 barrel carb., but I wanted to see this problem through to a solution before that time. I hate unsolved problems.

I wanted to report back so as to close out the thread (hopefully). So it "seems" that it was a carb. problem, possibly partly inflicted by an idiot carb. rebuilder - me.

Thanks to all who took the time to work with me on this problem.

 

Congrats! Drive it a bit to develop a baseline for MPG and then install 1406.

 

Good for you sticking with it and getting it fixed.


If that PV gasket was leaking then it may not of been opening and adding the extra fuel it needed?
Dave ----

 

Thanks Dave, I may not be smart but I am stubborn. I think the gasket was possibly blocking the PV openings or maybe leaking, not sure which.

Gary: I will check mileage a few times before swapping carbs if I can hold down my enthusiasm for that shiny Edelbrock.