I'm seriously thinking about switching the stock heads on my 289. Problem is I don't have alot of money to spend. Will 302 heads bolt right up? Would there be any gains to be had from 302 heads? If not what choices might I have with out spending over $250? Thanks for all your replies.
For all intents and purposes, 302 heads are pretty much the same as 289 heads. Take yours, buy an air compressor,die grinder, some porting bits, and a port/polish kit, and get to work on the ones you now have. All that's really necessary is to clean up the intake ports, gasket match them, clean up the area under the valves. The exhaust sides need the same, except the ports need to be open up, blended into he bowls, focus on raising the roof and sides of the ports, the floor just needs smoothing and polishing. You should also polish the chambers and unshroud the intake valves somewhat.
take D's advice. the 289 and 302 heads are essentially the same. you can pick up about 30hp by porting the heads. one thing though, dont polish the intake ports. you want a slightly rough finish to promote proper fuel mixing.
All of this assumes that you are working on a healthy engine to start. Throwing money and parts into it without analizing it firsr seems unwise. For example, if the engine is weak to start, camming it will achieve little. Check the compression, oil pressure, etc.
O.K. sorry for the lack of info. Car is a 1965 mustang "c" code fastback. The engine has been rebuilt but it has been a couple of years. I didn't do it I just purchased the car from someone on ebay and am currently doing a complete restore. I just ordered $4000 in new parts from a couple of different mustang magazines. So I don't have alot of money to throw into the engine. But I sure would like to get some horsepower. I'm going to rebuild the engine anyway(so I know that it is done right, this idiot I bought the car from did,or should I say "tried", to do certain things but didn't have a clue what he was doing. I no longer trust his handiwork.) so I figured I would throw in a new cam and intake manifold while I was at it. But I know that heads make all the difference in the world. Problem is I don't know anything about whats interchangeable on Ford small blocks. Anyway the the car has stock 2:80 rearend(I'm assuming) and a 4 speed manual transmission. I'm not sure what the gear ratios are on the tranny. I've already ordered ceramic coated tri-y headers. The carb 4bbl 600. I hope this helps.
If all you have to spend on heads or head work is $250, then save your money. You're not likely to get a set of heads that'll top what you now have for $150. I know that this is $100 short of your $250, but you will spend the $100 difference on gaskets, coolant, oil and filter, just swapping a set of heads.