Flexplate Fit -- "Snug"?
 

I'm installing a fresh TH350 in my dad's 75 Gentleman Jim, original 350 motor.

The instructions that came with a new set of Moroso flexplate bolts say that the flexplate should fit "snug" on the crank:

FLEX PLATE BOLTS
P/N 38760
INSTALLATION INSTRUCTIONS
Fits: Small Block, Big Block, and 90° Chevy V6 Engines
Contains: (6) 7/16”-20 x 11/16” Grade 8 Bolts with Washers
1. Prior to installing the flywheel, it is highly recommended that the
threads in the crankshaft flywheel flange be chased (cleaned) with a
7/16”-20 tap.
2. Also prior to mounting, check for a snug fit between the I.D. of the
flywheel and the crankshaft flywheel register.
3. Apply oil or suitable lubricant to the threads and install all bolts by
hand. Torque all bolts to 60 ft./lbs. in three stages. Begin at 20 ft./lbs.,
then 40 ft./lbs., and finally 60 ft./lbs. Always torque in a “star pattern –
begin with one bolt followed by the opposite bolt (180° away). Then
torque another bolt and its opposite, ending with the last pair.
REV. B 111513 38760INST

I have tried 2 new flexplates, one Summit branded and one Allstar (via Jegs). The Allstar has a slightly smaller ID than the Summit, but neither flexplate fits "snug" on the crank snout.

The flywheel I took off (with a Saginaw 4 speed) was snug on the crank.

Are flexplates in fact supposed to fit snug on the crank?

Re: Flexplate Fit -- "Snug"?
 

Can't say for sure if I have ever had one fit "snug". Sometimes I will have to kinda wiggle it on before it gets seated on the crank flat, but then I am able to spin it to line up the bolt pattern.

Re: Flexplate Fit -- "Snug"?
 

It is a close tolerance fit. It will still spin on the crank to line up the bolts but I doubt you could fit a 2 or 3 thousandths feeler gauge in there. If you could slip a .020 feeler gauge in there then you would have the potential for .020 runout on your torque converter. I think they mean a pretty snug fit with no side to side play at all.

Re: Flexplate Fit -- "Snug"?
 

I'm going to try a set of ARP bolts with shoulders on them and a different flexplate.