I pulled apart my motor and I found out that its got 351 heads on it.I had a machine shop check them out and there fine.Theve had over size valves,roller tip rockers,and duble spring vavlve springs.Are these heads better than stock 302 heads?Anyone know the flow #'s?
69 heads are preferable heads for that era. But that's in that era. To even go to the junkyard these days to get a set of 69 heads and go through the effort of machining them and putting them on the Stang is a waste of money. It's easier and cheaper to just buy better MODERN heads. Well, not cheaper really, but you'll get more for the buck that way.
the heads with larger valves and work, that the machine shop said was good, is cool!!
Stay with them , or upgrade to a set of PORTED E7s or after market. But the heads are cool!! ( If the work was done to them correct!!)
they can be good castings if you are on a budget. The fact that someone went to the trouble to put the larger valves in and decent springs is a good sign, b/c that is typically what can cost some dough. They should flow about 180 cfm on the intake even w/o porting, which is definately an improvement over 5.0 heads. Minor port work and 200 cfm is right around the corner. The other thing to check is the combustion chamber volume. Most 351w heads should be around 66cc's i believe in stock configuration, and if you mill that down to 60cc's or so, you should pick up some hp (assuming this hasn't already been done). Of course, if you want major HP, nothing can beat the new aftermarket castings, and if you go that route, you have some heads there that should be worth a couple hundred bucks to someone.