will a 89 s10 frame fit under a 2000 s10 reg cab?

no.............

I got the truck for free and I do this kind of work for a living so for me it's easy.

Thanx for the info Jim!

I find it easier to swap the drive train than the frame. Unless you can just find a frame laying around. But if it's a complete truck with blown motor or missing drivetrain, I'd just swap the drivetrain over. But to each his own

Truck was wrecked in front. Actually a rolling chassis would be ideal. Thanks guys.