Fuel Delivery

[rockman20]

Wow it has been a long time since I have been here. Been spending lots of time with my ride and work. For those who don't know and as a refresher, here is what has happened in the months that have passed.

I have a 82 Scottsdale K10 that was converted from the 6.2 Diesel to a gasser before I purchased it. Bought it, drove it, knew I had some problems and started looking around. Decided to get a new engine. I wanted to build my own but with winter coming, I wanted to A) not freeze my nuts off and B) get my 4WD out before the snow hit. So I ordered an engine from an area builder. Stock 350 with flat top pistons and Comp Cams extreme 4 X 4 cam. I slapped on a set of headers and an Edelbrock performer intake. (Looking for low end power, not high end) Shortly before I did the engine, the transmission decided to puke all its vital fluids out. Checking into that, I found a bad torque converter (due to the spun bushing), a spun bushing, and basically fried bands throughout the 700R4.

So now the truck is sitting with a fresh 350 and a fresh 700R4 with fresh torque converer. It runs and it moves but I am horribly depressed with the power. Sometimes that is. Some days the thing will run awesome. Great torque, great acceleration, great everything. Then other days it is like hopping into my 94 Honda Civic. There is NOTHING.

Troubleshooting I think I narrowed the problem to ignition. Appears like mechanical advance is sticking. Tried to cure it with some silicone spray but no avail. Since I have already put more into this truck then first anticipated, I looked at remanufactured GM HEI distributers. Found one, slapped it in, thought I was good to go. Truck sounded different now. A lot more of an aggressive roar under the hood. Thought that I had cured my woes.

Nope. Stupid thing still acts up on me. Now I am turning my attention towards carburation. I have gone through this thing once already. What scares me is that the guy who worked on this before I did was a supposed mechanic. He supposedly was good to. But the things I found when I took this engine out would make almost anyone cringe. Motor mounts that were smashed in because he couldn't get them to fit right, double nuts on almost every rocker, a lifter that exploded and tiny retaining clip out and so the center of the lifter was sticking out and wouldn't move. To compensate for this, he just turned the nut on the rocker way out so that the valve would at least close. (No wonder why I had uneven compression and poor power!)

I didn't notice anything horribly wrong with the Rochester, but I guess I didn't look real close for some possible drill marks or anything like that.

So after this huge long post, here is the question. For a 4WD pickup that does some towing, does some mudding, does some snow running (especially now!), and gets driven as a daily driver in the winter time, what kind of carb would you guys suggest.

I have an Edelbrock Performer on my Cutlass and I really like that and I am thinking that maybe I should stick with one of them. (If the carb will fit on the intake. I had to add some spacers to my Cutlass to get the Performer to fit on the Performer intake) But I also saw that Holley has a truck carb. 670 CFM that is built for rough terrain and some pretty steep grades and is calibrated for the low end torque and power. My fear is that Holley name though. I have ran a Holley 600 with vacuum secondaries on my Cutlass once and I hated it. The stock Rochester would out do that thing without a problem. And I also fear the tuneability. Would that carb hold a tune or would I have to mess with it on a monthly basis? And finally, the notorious power valve blow outs on the Holleys. Would I need to modify that with the check valve to protect them or is this issue taken care of on that carb?

If the Holley isn't the way to go, what else would you guys suggest? For the price of that Holley, would I just be better off getting a brand new Rochester Quad? Then I wouldn't have to mess with fuel lines, linkages, etc.

Oh, the truck has the divorced style choke which I believe is part of the problem in these temps. I do not believe the aluminum intake gets hot enough to pull the choke off completely. Especially on days like today where the temp. started at a balmy 35 below zero and has warmed to a blazing 24 below zero as of almost noon.

Thanks for the info!

[jared stewart]

If you look under my posted question of "Which carb to use" I had several people suggest a 600 cfm Edelbrock and I have pretty close to the same setup as you do. Also had some mention going to a Carter because they're cheaper but just as good.

They tell me that the Edelbrocks are a lot easier to tune and they now have come out with their AFV (I think) offroad series that is supposed to be really good in rough terrain.

[69ChevySteP]

i said carter. i got one a while back and will never buy anything else

[1972C10]

yeah carters are just as good seeing how there the same carb

I can tell you the only difference edelbrocks have screens behind the needle and seat and carters dont other than that same carb


If you go to build an edelbrock the kit is 50 bucks you can get a kit for a carter for 20 just have to reuse them screens.

[Tom]

I've run two carters and an edelbrock over the years. They all suck. They stay where they are tuned and are extremly easy to tune though, thats why I still have one on my daily driver. Dont wanna mess with it. Demon makes some sweet carbs. Loved mine.

[1FaastC10]

what kind of cam is in it? have you messed with the carb tuning? are you 100% sure the valves are adjusted properly? were your springs replaced? with the correct springs for the cam? what do the results of a compression and leakdown test look like? specifics on the engine (heads, cam, CR, etc.) also, what does your fuel pressure look like? did you replace the pump?