71 340 Compression Test

1badfish67 said
Well I got the 340 out of the car. I found something interesting. Block date shows 6/71. Intake shows 12/71. I just pulled valve cover and head number is 3671587 also has 'AAWJ' 360 on it. What I have found so far on the net is these are 1973 heads. So looks like small 1.88" intake valves. Looks like things can sit around for a while on the shelves. So the 8.... CR seems logical and this is the chocked down 245 hp version.
Looks like I am going to give her more spunk and rebuild. Is it true that these heads were designed to be able to cut new valve seats (2.02") into the heads.
Can anyone recommend a maximum CR to run on say 91 to 93 octane pump gas? Could 10:1 work.
There is a racetrack a few miles from my house and a station that carries race fuels including what I hear is called '100-Low Lead.

Thanks

Everyone who has commented. Good information.

Yes, the heads can take a 2.02 valve. I have them myself on my J heads. 2.02 valves, a bowl cut and clean up does wonders for flow. Makes the heads easily support 400 HP. As for compression. Dynamic compression matters much more than static compression. With iron heads, max on pump premium is 7.5:1 dynamic compression. Pay attention to quench as well. As it's just as important as compression ratio.

Race fuel gets expensive if you wanna drive more than on friday/saturday nights. 100 low-lead is aviation gasoline. It's fine to run in vehicles (up for debate according to some) just make sure you get hardened valve seats when you get new valves.