Thanks for the reply. I have heard all different ratios when it comes to this engine, everything from 10.25:1 to 11.00:1. I think I'm going to try 10.25:1 on my rebuild, we can get 94 octane gas here no problem, the only thing I'm worried about is, if I went on a big tour through the USA, if I would be able to get good enough gas, I have read a few posts where guys have said the gas in their area wasn't real great.
I live i n New York and I use Sonoco 93 and have no problem with the fuel . No pinging at all. Which model Lesabre do you have ? I have a LeSabre 2d hardtop Custom 400 Nice little 300 motor.
My 300 is in a '65 skylark, I plan on a strong running 300, with a 200R4 transmission and 3.73 rear gears. I have only gotten as far as getting the frame painted so far, but I WILL finish this thing within the next few years! This is my first project car, so I'm learning lots.
Good looking car you have there!!!:TU: The chrome looks awesome How much work did you have to do to get it that nice and straight? Does a 300 move a car that big along ok.
The car is a never ending project. But its older than all my kids and has outlasted 2 wives. We'll see how the 3 wife does with it. It's no race car but it can get out of it's own way with the 300. The car weighs 4200 lb. It does OK Tony
the stock 2bbl 300 was 8.5:1. The stock 4bbl was 11.5:1. Poston Enterprises in Atmore, AL offers both sets of pistons. . The 11.5:1 repros are actually 11.2:1 This is the way to go and you'll be fine on pump gas
a key factor is to smooth out the combustion chamber on your heads also unshroud them, you dont have to get them baby smooth just remove the sharp edges and ruff spots, do this to your piston tops also. that is what causes almost all detanatoin, if you do this you should have no problem till you get near 10.75 to 1 comm.
There has been much debate about this... Here is the correct info: 1964 2bbl ?? (Forgot) 4bbl 11 to 1 1965 2bbl 9 to 1 4bbl 10.25 to 1 This info is directly out of the Chassis sevice manual... HTH
