I have a T56 Magnum with a Quick Time RM-6023PB, now upgrading going from a SBC to LS3.

(I have a mechanical fork, which I'm realizing I'll probably have to ditch for a hydraulic setup and I'm fine with that.)

The Quick Time LS bellhousing (RM-8020) is 5.500 inches while the RM-6023PB is 5.950 inches. (So I have .45 inches increased difference.)

I really really would prefer to reuse my current BH as these things are mega $$$.

To make up the difference I know you can get extended pilot bearing made exactly for this.
Then the flywheel, McLeod makes a flywheel which is .4 thicker, but is $400.

So what I'm wondering is instead of getting the .4 thicker flywheel, is there any reason you can't put .4" of spacers behind the "collar clutch release bearing adapter" for the T56 that the TOB resides on (or in front of), hence bringing the TOB closer to a stock sized flywheel?

It seems like a more cost effective solution.