Yes,early crank can go in later blocks INCLUDING LA 318's!

From: Daven Anderson
Email: [email protected]
Date: December 22, 2001

Comments

Putting the pre-'62 crank in the '62-up poly 318 block will indeed allow it to be used with the original '59 transmission parts. Yes the rods will work. I have not heard of anybody using a pre-'62 318 crank in an 318 LA block,BUT it would work assuming a pre-'62 transmission setup was behind it. The main bearings and rod bearings are the same dimensions (and the stroke is 3.31" for both),so if you did this the 318 LA rods would hook right onto the old 318 poly crank. (318 cranks do not fit 360 blocks because 360's have larger main bearings) The experience I have is the reverse of what you want to do,putting the '62-up 318 cranks (poly or LA,doesn't matter) into the early poly blocks to allow use of the '62-up trannies which are higher performance and easier to get parts for. The '62-64 A-727 weighs 65 lbs. less than the '57-61 Torqueflites and shifts with the '57-61 dash pushbuttons (the cable directly hooks up!). Also,later 3 speed manuals will have synchro first gears and more choice of gear ratios. Of course later cranks allow the use of modern 4/5/6 speed manuals and overdrive automatics for those less concerned about 'original' appearance. That said,there is no reason why you cannot put the old crank into an LA 318 and use the car's original transmission behind it. The LA 318 does weigh 70 lbs. less than the poly,so you'd save weight in front.