I have two motors. One is out of a 1970 Torino gt and the other is out of a 1986 F250. I plan on using one in my 68 2wd and the other in my 72 4x4 trail rig. I'm leaning toward using propane on the trail rig and want lots of low end torque from a reliable package. Now for the 2wd 68, I'm hoping to end up with a nice muscle truck when I'm done. Nothing too radical but definitely pins me to the back seat when I stomp on it. My question is, among the different stroker sizes, is there some sizes that are better than others? No replacement for displacement as people like to say. So is bigger better?

 

for longevity I prefer the 4.3" stroke as it's a nice compromise on size with a slight less side loading then the 4.5". It's not a huge amount but over the long haul will make a slight difference.

For absolute power only prospective, yes bigger is better. So if your looking for a power motor that probably in it's life won't see 50k miles then sure go with a 4.5. If your looking for a motor that has good power but you just plan as a driver then I say 4.3

 

I would also use the newer block.