I have the stock heads on my 67 396 in a 70 chevelle w/ a th400. My question is, what kind of work can I have done to these heads, about how much will it cost to have someone do it, and what gains can I expect to see. The engine has a Q-Jet, Torker 2 intake (will get an RPM intake later), 2in Hooker headers and 3in Flowmaster exhaust. very little if no work has been done to the internal components. The car is street driven, but that doesn't mean I want it to be a slug! Any input would be appreciated. Thanks guys, Matt.

Hey Matt,
You might be interested in reading the post about adding larger valves to a 396/402 as it is a similiar question. A 67 396 should have a closed chamber combustion chamber. You did not state if you have oval or retangle port heads. My experence is that some bowl work will help most of the old factory heads. Larger valves(for oval port heads) are another option you may look into. Most machine shops have someone who ports heads. You might ask around to see if there is a recommneded shop/person in your area. I would think 300-400 for a basic bowl job would be in the ball park. The sky is the limit on head work for cost. But probably 80% of the gains are in a standard 300-400 port job and the other 20% can cost a small fortune. I would think a port job and rpm intake would help you engine alot.

And, imho, your 2" headers are too big b/c 1.75" jobbers do very well on motors up to and above 500" b/c they enhance torque production in the lower rpm ranges...

pdq67

I am going to save you a lot of time, energy and expense. Unless you intend to go the whole route of having the heads ported and the chambers reshaped, save your money and stick with the stock valves. If you decide to go with larger valves afterall, you will may have to have the valve pockets in the pistons opened up to accomodate the larger valves, dependent on exactly what pistons are in there, how much the heads have been cut and how aggressive the cam is. If you do not get this right, you will find yourself with a pair of heads with bent valves. I know this firsthand. IMHO, just go with a decent cam upgrade and enjoy it. If you really want big power, put in a bigger motor.

My #215 closed chamber heads only had a valve job..left the stock valve size too.No hardened exhaust seats either.No port work...seem to work fine for my combo graemlins/thumbsup.gif