quick question is it worth it or woulld you feel a difference in porting and polishing stock 302 heads?
I always do at least a gasket match on the openings and get rid of the exhaust bump. I think it is definately worth doing that.
I have air grinders and dremel tools - so the only cost is my time and a bit or two I may burn up. My guess would be $150 or so to have a machine shop do it but that is just a guess. Any engine building book will teach you how to do it if you want to try it yourself. As far as feeling it? I have never done just this one thing to an engine. It is just one part of an overall rebuild to wake up the sleepy stock 302. When all my mods are done you better believe you can feel it ...............
then i guess my real question is, what does that do? btw i forgot to mention i have intake mani. 4bb holley, and exhaust
IMHO, if you are doing it yourself, sure. If you are spending S200 or $300 then i would suggest you don't sink any meaningful $ into that head as they are not very good. You can pick up a set of the 69 or 70 351W castings pretty cheap that are a much better flowing head than the 302. There are a lot of options available depending variables like budget, goal, and originality but as far as performance, I don't feel that significant $ into that head is a good investment.
You can check out aeroheadracing.com. I have not been a customer, but it doesn't look like a bad deal.
I did a set of E7TE's several years ago, but did the work myself. All I did was port match the intakes. On the exhausts, I opened the roof and sides of the ports out to match the header gasket, then blended this all the way down into the bowl area under the valve, removing the Thermactor bump in the process, I also bowl blended the area under the intake valves. Was it worth it ? If you compared the exhausts in a before and after pictures, you would see the 100% improvement in volume of the exhausts. I cannot give you dyno numbers, but just knowing how much better the exhausts flowed in my mind, it was definately worth the effort. Plus I only paid $50 for the heads, and the valve job after I'd done the work only cost me another $125, plus another hundred for new springs and retainers. If you have heads that need new guides and valves, then skip porting and start hunting for better aftermarket heads.
Yes...and yes. You need a set of either insert reducers or a enlarged shoulder head bolt to do it correctly . Reason being that stock 302 head bolts are 7/16s where as 351s use a 1/2" head bolt. You will feel a difference as long as you have a decent carb, intake and headers to take full advantage of the increase in airflow.
A more reasonable option would be to look for a pair of GT-40 heads from an explorer and measure for proper push rod length. They already have the hardened seats for today's unleaded gas and are easy to find.
You don't need either the bushings or larger headed bolts. The block dowels locate the heads, same dowels for both engines. I just put together a GT40 headed 302 with heads from a 351W lightning. I used a plain jane set of early 302 head bolts.
I assumed you at least used hardened washers. Yes that will work, but with internet advice it's hard to determine the mechanical ability of OP.
Alex, There are a lot of good suggestions here from a lot of good people. To better help you, answer 2 questions and you'll get many good suggestions that fit your parameters. Can you do port work yourself? What is your total budget for heads?
If you ever want to have them done our Porter here was rated one of the best There is we do super stock motors. Beachy machine
