Ford 4.9 300 I6 vs 5.0 302 V8

[360 4V]

My torque converter has two stall speeds depending on load. Under low load conditions and/ or part throttle, the rear wheels will start moving at 1,500 rpm. Under high load conditions and/ or full throttle the rear wheels will start moving between 2,200 and 2,500 rpm. This torque converter was selected by its manufacturer.

How much cylinder head is about right for this stump puller 302? I have read lots of good results from 145cc and mildly ported GT40 cylinder heads. I am not sure if 165 and 185 cc cylinder heads are bleeding off torque on a 302.

 

[broncnaz]

I've heard of those converters before not real popular today but I guess they work I think I'd rather have one with a single stall to lesson the chances of a malfunction. My understanding is they were used on many of the old gm big blocks to keep the vehicle from creeping through a stop sign. Not sure how well they would work on a small block. Small block converters rarely have a stall speed under 16-1800 rpm. really for what its worth todays transmissions with lockup converters are a much better choice. but like I said I'm not well versed on torque converters so its only my slightly educated opinion there.
I'd stick with cylinder heads that have valves no bigger than 1.90/1.60 on 302's with bigger heads there tends to be minor losses of lowend 140-170 cc should see no loses and if any it will be minor. Even with larger heads losses tend to be small. If you have gt40 heads and feel like porting them then it probably wouldnt hurt and they should do all you want them to. If you have to buy the heads and have someone port them then the cost is not worth the effort IMO. I'd look at any aftermarket head as they will be better out of the box then ported gt40's and will endup costing about the same but provide more power.

 

[360 4V]

I don't have a switch pitch torque converter. Flash stall is the rpm that the engine flashes to when the vehicle is launched from rest at wide open throttle. I know this one. My flash stall is 2,200 to 2,500 depending on the engine. The other stall speed, 1,500 rpm is either true stall or brake stall. Dirty Dog said that with my application, he expects the wheels to begin to move at 1,500 rpm unless I am reall launching the vehicle in which he would expect to see 2,200 to 2,500.

If I took my 359W out and put in 302 the stall speed would be less?

Back to our stump puller 302; I am thinking that if peak torque happened at 2,000 rpm then a flash stall of 1,500 would be about right. Isn't flash stall the stall speed that should be 500 rpm lower than peak torque?

http://www.carcraft.com/techarticles/selecting_right_torque_converter/index.html