1974 chevy c10 problem

First, I'd look for a vacuum leak or something silly like that. Maybe your vacuum advance is hooked to the wrong place on the carb. You could start with the standard timing and see how it behaves. Then advance 2-4 degrees and see if you can tell a difference. Repeat, if you like the results. Eventually, you'll hear knocking and know you've gone too far, if the performance hasn't declined before you get there. Keep a record of where you are and what the results were.

Is the respiration system a reasonable match for this engine? I don't know how much air/fuel your 350 needs. If you are still using the stock cam, pistons, heads, etc., you may not be able to increase the respiration much with good results. Too much air/fuel may make it bog down.

Good luck and let us know how it comes out. .

what intake of holleys did ya use? dual plane? low rise? high rise?

well it is a little higher than the stock intake that i took off so i would say a high rise intake, also i had to put a 1 inch spacer so the carb would go into 4 barrel.

i took my truck and got someone else to adjust the timing and the carb. it ran great all day. late this evening i got in it and started to town it ran okay, but when i left the store the temp hand was still above 100 degrees on the engine and it did not want to start acted like the battery was dead but its a new battery. i guess the timing is still low but dont understand it ran great great early today and i could cut it off and it would crank fine, now i am not sure what the problem is....

the higher intake and open spacer would raise the powerband into the higher rpm range making sluggish acceleration down low. advancing the timing would help the acceration, but would make it difficult to start if advanced too much and when it's hot. in your previous post, you mentioned the adapter to mount the carb. i'd check that area too for vacuum leaks because some of the adapters don't completely cover the mounting areas causing a leak @ times. this plate adapter may help: Edelbrock # EDL-2732. hth

Check the timing, also check that the vacuum lines are properly routed. Also check for possible obstructions in that little piece of metal tubing that the factory put on the stock vaccuum line just before it goes into carb. I had something of the same problem, it turned out that line was clogged with gunk.

That carb might be too big for your engine. You might want tosimply rebuild the stock carb. That's what I did when I put a new 350 into my 77 C-10 which should be about the same as yours.

The vaccum l>I have a 1974 chevy c10 with a 350ci engine. I just recently put a 670