Well, I just discovered from my mechanic that my 68 small block is actually stroked to a 383 with open chamber heads and VERY high compression (maybe 12.5/1). I have a persistent pinging on acceleration, obviously. He recurved the HEI, put on an adjustable vac advance, and the total advance must be retarded to 20 BTDC or so to make it driveable without the ping. Giving up an awful lot of performance that way. He is suggesting that we try an octane additive to see how much more advance it will tolerate with that. Any thoughts? If we go the additive route, any specific suggestions as to best additive from both results and price perspective? Thanks,

Jim

 

There isn't pump gas out there that will let your engine run without pinging, octane boost is going to be needed. Just pick up a bottle at your parts store and try it, I don't know of any "bad" one to use. Another option instead of octane boost, is to put on a water-water/alcohol injection setup. google it if you don't know about water injection.

 

You can buy racing gas, or figure out the right dose of Octane boost, but you'll never get it consistent between tanks.

With the high compression, your a prime candidate for an e-85 conversion. In the long run you'll save money on gasoline and in the short run you'll get better performance. Check out the link below for guys that are already doing it. It's the real deal!

Race on E85