Im wanting to do a complete rebuild on my engine, top and bottom. Saw a cheap pair of used gt-40P's and a 347 stroker kit. Would the 347 kit be to much for them? I was also thinking about porting them a little more. Yes I do know about the header issues on these heads.
Yes, the 347 would be too much for them. It would run, but you would basically negate the extra displacement of the 45 extra cubes by choking the motor with the GT-40P heads.
I would say it would be a good running motor if you do a little porting on the exhaust side and use a decent cam. Not a race motor, but a good street motor. You don't need huge heads to make good power, just a good combination.
I would say it would be a good running motor if you do a little porting on the exhaust side and use a decent cam. Not a race motor, but a good street motor. You don't need huge heads to make good power, just a good combination.
I think a full port job to the gt-40s and a bigger set of valves. Whats the sense in taking the time and money to build a STROKER and then put a set of heads on it that dont take advantage of the motor. A full port job to the gt-40s and they will be OK.
A good set of heads would be ideal but the gt-40s with some work would be alright.
There is no reason to put GT-40Ps on top of a 347. The only place you will see a good gain over a 302 w/GT-40Ps , is bottem end torque. Shell out a few hundred more dollars for some good flowing heads w/ 2.02,1.60s. Also purchasing GT-40P heads then having them porting and putting in larger valves, would probably be more expensive and still not flow as good as a good out of the box set of aftermarket heads.
There is no reason to put GT-40Ps on top of a 347. The only place you will see a good gain over a 302 w/GT-40Ps , is bottem end torque. Shell out a few hundred more dollars for some good flowing heads w/ 2.02,1.60s. Also purchasing GT-40P heads then having them porting and putting in larger valves, would probably be more expensive and still not flow as good as a good out of the box set of aftermarket heads.
Port them yourself, it's easy if you have any idea of how air flows in an engine, and you don't realy need bigger valves. Also a 347 will make more power than a 302 basicaly everywere, not just bottom end as long as you run the proper camshaft to support it.