Hi all, this question probably exists in a few different ways but not all heare all at once.

For the 91 Z28 TPI vert I'm picking up this weekend:

I'd like to take an AL. head 350 or 400 Ci block (maybe 377 destroker) with big hydraulic roller cam, (and low profile roller rockers) Canton road race pan, and top it with LT1 injection (LT1 John style) with a goal of 425 RWHP.

Can I use the stock, existing TPI harness from my 305?
I always heard I would need a 1991 speed density computer from a 91 vette to make this work?
Is this true?
What ECM is in the 91 Z28, MAF or speed density? and will it work?
Would I need LT1 edit to tune it?
Will the TPI throttle cable work?

Anything else come to mind?

Thanks
Evan