dont these out flow ported 317s stock?

 

Here are the specs::

Lift .200 .300 .400 .500 .600
intake 151 208 256 294 316
exhaust 111 152 174 183 189

 

Ported 317s will flow similar on the intake, but much better on the exhaust. Also, the L92's have a massive intake port compared to the 317s (i wanna say 268cc's versus 210 cc's for the 317s stock, and typically 225-230cc's ported). I've wondered how that would affect throttle response.

 

Doesn't 12sec5.3 run these heads and intake combo.... I beleive he is hitting 11's on motor with his 370...

 

To be exact these heads are a 260cc intake runner, and with that there is alot more to this whole bottom question.. Yes a larger intake runner will effect the bottom end performance but with that said there is also alot of ways to compensate that with compression, gearing, and the right cam choice....these heads will work great with the 6.0L engines and bigger its a great upgrade for the price....

 

bump for the day

 

Got these heads, and was just amazed the type of head these are for the price. Got the heads bare no need to buy complete heads if there getting all new parts. GM actually got these right...
The ports in a NON cnc option need a little work right around the guide area.
Thanks Chris for getting these out to me so quickly. And hopefully another 6.0L would be nice.

 

thanks buddy glad you like the heads...I havent forgot about the 6.0l I am still keeping a eye out for ya...If I come across one you will be the first I call....