Which Flathead?

I'm building a 34' p/u. I have 2 flatties: one is a 50 out of a shoebox, the other is a 49' out of a truck. Which has more potential? Thanks.

 

You'll have more speed parts available for the shoebox flatty, that's for sure! I can't find anything for the 337.

 

***uming that the one out of the truck is not a 337c.i. engine. Both engines are good to use. The truck engine has the preferred water pumps, but other than that the engines are vertually identical.

 

A good "bible" for rebuilding flathead's is Ron Holleran's, NOSTALGIA: REBUILDING AND MODIFYING THE FLATHEAD FORD V8. Although all models can be warmed up, he recommends the later 8BA as having the most potential. Hope this helps.

 

Thanks for all of the input. When I picked up the shoebox flattie the guy had a bunch of stuff in his trunk he gave me. One being a pair of Merc heads and an Edlbrock tripower intake....do they even make that anymore?
I had a 9" rear off of ? But, I'm trying to keep it 50's(this is a challenge). I gave the 9" to my buddy for his g***er project and karma came right back around, today I put a 50 Merc rear in. It worked perfect. Just a little update of where I'm at.