[68_Convertible]

I just finished removing rebuilding and putting my engine. Had a machine shop build the long Block. The engine is a 1974 Chevy 350, Flat top pistons 10:1, 224/224 cam, had the heads done new valves, guides, seats and springs. Mallory Magnetic breaker less distributor. Holley 600 CFM carb and a Dual plane RPM performer manifold. Headers and dual flow master 40's.


1. Anyone know what the initial timing should be? I tried 4 BDC, that was no good, I tried Timing it at 3000 RPMs and setting it to 36 degree. That put the initial timing at 14 BDC. Seems a little high?

2. What spark plugs should I be using, I have Bosch plugs in there now because I the auto parts store did not have Accel plugs in stock?

[johnsongrass1]

I really like the bosch plugs. Keep them
14 degrees at the crank sounds good to me. I have a cam a little bigger than your's and it likes 18 at the crank and 42 total by 2600. If it doesn't ping than I think you should run it. You can always change it later with timed runs t really optimize the timming.

[figure8]

I would try about 32 degrees total advance with the vacuum unhooked. May have to wing it to 3500 to 4000 to make sure mechanical advance is fully advanced. If it pings when you hook up the vacuum, try backing off by 2 degrees. I f you cant hear any detonation you could go to 34 degrees but put it back if any ping. Phil

[68_Convertible]

No vacuum Advance. Magnetic breakerless distributor. Need a special kit to get the full curve out of the timing. I am trying to locate one so I don't have to order it. I can set it to 36 BDC full advance (no pinging) this is what it used to run at before the rebuild, but the cam has changed a little since then I had a 214/224 now I have a 224/224.