74 318 crankshaft

Hey Guys , so assome of you may know had a bit of a problem with coolant in my Oil on my 410 stroker motor. I'm going to address this problem hopefully not having to pull motor . The car that this engine is in was once my Daily driver and was going to continue to be once swap was done. Now IF it comes to where motor has to come out I'm going to pull it and put my bonestock 318 back on but want to. Leave the 4 speed in it.as well. As my 8 3/4 rear til 410 is reworked. Now my question is how do I know if m 318 crank is drilled for the 4 speed? Also my flywheel crank and balancer (from410) were all balanced together. Can I throw this flywheel on with out any problems??or will Ihave a balancing issue.?? I plan on doing this only if my 410. Has to come completely out

Thanks guys