Aluminum 340 heads

[EVIL72]

I typically get a 41 hp gain swapping on juckyard 308 truck heads , great bang for the $$
 the eddys I looked at were not as well designed as the 308 heads & had bad core shift

Chryco when you get 41 hp what all are you doing to these heads? Are you adding oversized valves too, if so what size valves? or do you just do some pocket porting and port matching?
 
 
 

[Harkonnen]

I wonder how the 340 HEMI heads perform compared to the x-heads

[Chryco Psycho]

actually that is using the stock 1.88 / 1.60 valves but with porting done both in the pockets & opening up the heads at the gasket , the pushrod wall cannot be opened up extensively due to the larger than nomal hole for the pushrod but the exhaust side can be opened up a lot on the roof & sides of the port , I do not touch the floor of the port
you can install the 2.02 intake valves as well

 I have no experience with the small block Hemi heads so it is hard to say how they would peform

[EVIL72]

 Thanks for the info Chryco, I'll have to hunt down some 308's for my 340 to go along with the Air Gap RPM I just picked up.

[Chryco Psycho]

Ok , You are welcome