Hey all this question pertains to what kind of hp increase I will see out of a mild to heavy port and polish job on these heads and maybe have a little bit milled off of them while they are there. (would it be the same as an old gen chev) Friend of my dads owns a machine/engine shop, I am thinking I might just get him to put the springs in and while there there have the head work done. I just want to keep it basic, is there any special tricks to these heads over a old gen chevy head(thast for me to know). Any input on this would be great.. thanks all JOHN

 

They flow a hell of alot better than the old SBC stuff so you arent going to see as significant of a gain as with them. You could probably get 25ish out of them judging by some of the dynos over on tech with mild setups.

 

Not trying to sound like a jackass, but I'd make sure your dad's friend is experienced with porting the genIII heads. They can be overdone and end up hurting your power.

 

Nah not at all thats why I asked, because I rember hearing something somewhere about that. I will have to make sure that he does know this, as i was saying that shop is mostly into the old school prostreet/blower type ****. Thanks for that info

 

If you're looking for a good P&P on GENIII heads, I'd be looking towards someone with a good CNC program. As mentioned above, these heads can be made into paperweights real easily, and there's alot of good CNC options out there. I'd recommend WCCH...customer service is second to none, and the craftsmanship is excellent. I checked with a reputable local race engine builder about hand working these heads, and he gave me the same advice...to make it worth your time and money, go with someone like WCCH.

*EDIT* I noticed how you mentioned that you want to keep it basic...so I'm assuming that budget is a factor also. The good news is, these heads are pretty darn good right out of the box.

 

317 heads already flow pretty good,the porting is the same as LS6 heads with 72cc chambers instead of 64cc chambers.Unless you are planning really big cam,they should work really well as delivered.

 

I agree with Whitt. If you are set on doing some headwork, I'd also contact Richard @WCCH for sure. He seems very helpful and takes a special interest in us truck guys. If you are set on someone local, you can PM me for a recommendation. The shop I have in mind has over 25 years experience, including LSX based engines. They have a flowbench as well as an engine dyno. I used them before on a set of Dart II heads for a GenI small block and made a noticeable gain. You could also check the thread I posted in about race gas, as I mentioned the shop to Whippled496 as a VP dealer. PM me for a link.....but I'd rather see you go with Richard!

 

got mine from Richard(Very Nice Guy), You'll like it very much!!
will notice big power difference at top end with bigger cam.

 

Ok thanks alot guys, will have to make some calls, such. Next ?? is, I have a tsp 224/581 112 cam on the way. So will these heads work fine the way they are stock or will the pp job compliment the cam even more.. Thanks again JOHN

 

If you have them off the motor,do a good valve job,mill them about .020" if you plan to run premium gas and install some new Comp 918 valvesprings.Then spend you money or a set of long tube headers.