1964 plymouth valiant Slant six to 340
Probably be a good idea to go thru the suspension change radiator torsion bars rear springs. Unless you have already done all that.
I have a 64 that was transformed from a slant to 318.
Half *** hack job. I have since fixed that mess. Now have A upgraded 318 roller going in .
It will have enough power for me.
Not going to see the track. Good luck with your project.