timing

[74chev4x4]

74 Chevy 350 with 305 heads, I have it timed at 12 degrees and it sounds good but seems to be running rich. It does not respond when I floor it it just slowly comes up to speed and when I get off the gas it will backfire once or twice. It runs Ok but not much power. Any advice on where to time it motor is stick with a mild cam and 305 stock heads.

[Grim 82]

Maybe back it off a bit and see if it changes. Try 8 BTDC. What condition is it in otherwise, as far as tune up parts? Sounds more like carberetion than timing.

[Lt.Del]

perhaps accelerator pump?  perhaps vacuum leak?

[Irish_Alley]

Did it just start or did you do something. Usually if its to advanced you will get a spark knock so it does kind of sound like a Carb problem have to know more

[74chev4x4]

Just did the intake manifold gaskets to fix an oil leak, put it back together ran great went for a drive and it started stuttering and backfiring. Plugs, wires, cap, rotor, coil are all new. Motor is pretty solid, but the heads r not in the best shape. I can see a lot of blow by coming out of the breather and its in there tight. I will clean the Carb and check for vac leaks and adjust the timing.

[Lt.Del]

spray some wd40 around intake gasket and hoses and carb base when idling and see if rpms go up.  I bet the gasket on the intake slipped or something.

[Irish_Alley]

Do Sgt said. Did you have to readjust the settings on the Carb?

[VileZambonie]

350 with 305 heads

Problem found....

[74chev4x4]

yea not real happy with the 305 heads either but that's what it had on the motor, sprayed around intake no change at all. Did nothing to the Carb but take it off and put it back on.

[Irish_Alley]

Stupid question but you sure the firing order is right? And all have good connections

[74chev4x4]

I will go double check the firing order, but would it run this well if they were off?  Thanks guys.  Also I keep thinking about swapping the heads on this motor, but have never done heads on a small block.  Is it as easy as take the intake off unbolt the heads do head gaskets put new heads on and bolt up the rockers?  Can I use the same pushrods lifters and rockers if I just go to a set of stock 350 heads. I would really like to do this to ditch the 305 heads, but not sure how hard it would be.  Thanks.

[74chev4x4]

found the problem, the number one spark plug wire is arching across the header tube.  I tried electric tape around the boot, stopped it for a few mins, now its arching again.  Whats the best fix for this new wire?  These are the 90 degree boots for headers also.

[Grim 82]

You probably can't save that one wire, but on the next one use these asbestos sleeves. You can get them at o'reillys, etc. Mine are touching the header and they haven't even shown discoloration after a few thousand miles.

[Lt.Del]

new wires arcing?  solution?  Take 'em back where ya got 'em from and demand replacement or money back.  Most have warranty.

[74chev4x4]

Bought those spark plug boots like grim said, but was only able to by 1 2pk because they are $20 bucks a pack, so hopefully this takes care of it for now until I can swap those heads out for some decent 350 heads, I need to look into how difficult this will be.  Thanks.