JUST WONDERING WHO HAS SEEN THE BEST FLOW NUMBERS OUT OF GM LT1 HEADS. HAD MINE PORTED. STOCK AT .500 LIFT IS AROUND 220-230 AND THEY FLOW 264. ANYONE SEEN BETTER FLOW #'S. THE NUMBERS DO KEEP RISING AS THE LIFT GOES UP.

 

we've gotten some to 300+...
it's tedious and you spend a lot of time on the flow bench.

 

Heads that flow around 275-280 are terrific for lt1 castings. Your 260+ is good for a decent stage II if thats what your asking.

 

Wow, I've never heard of anyone getting 300 cfm out of a stock LT1 casting. What lift was that at???

Joe Prince did my heads and gave me the following flow numbers (no exhaust numbers except .550 was 210)

.100 = 70
.200 = 140
.300 = 204
.400 = 231
.450 = 242
.500 = 262
.550 = 272

I'm betting that it would be in the 280's at .600 if he had flowed that high. He said he left a bit on there because he was matching it to my cam (224/230 XE). I'm pretty satisfied with them. Making the most RWHP with that cam that I know of, stock bottom end at least.

 

ok i found my flow # sheet.
ELLIOTTS PORTWORKS DID MY HEADS.
STOCK #S ACTUALLY DONT FLOW OVER 211.7CFMS EVEN W/ THE HIGHEST LIFT.
DIDNT ADD BIGGER VALVES BUT AFTER PORTED THEY ARE
.500 = 246.6
.550 = 255.9
.600 = 262.8
EXHAUST SIDE LOOKS TERRIBLE.
.500 = 157.4
.550 = 164.5
.600 = 168.5