Thread: Pontiac 400 Timing

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I need a little help. I just got my 70 GTO back from having engine work done. Some of the mods are: .10 ground crank, bored .30 over w/new pistons, comp cam (268 I think), roller rocker, 1968 428 heads with new valves, gear drive, edelbrock torquer intake and 750 4-barrel and electronic ignition converstion.

My problem is under a load the engine will pop and ping and have no power. I haven't broke the engine in yet to open it up going down the road. I am assuming the timing is to far advanced. I am running 93 octane and my compression ratio is approximately 9.5:1. Any suggestions on what the timing advance should be??

Thanks,

JT

In some books that I've read they use 93 octane from 10.5 compression only.
Try to run lower octane. And write me back at this e-mail and I will look in my performance books to see the correct timing.
Rick_Fireheart@hotmail.com
The crank was grounded .010 but did they put special thicker bearing?
If not your crank will not turn correctly because of too much clearance.

So write me back.
Rick