94 TBI Bottom end on a 98 vortec top end

[GavinJansma]

Would a 94 TBI Bottom end fit on a 98 vortec top end? I understand that I will have to swap timing covers and such but will the Vortec heads bolt up to the TBI block?

 

[Schurkey]

If you use the Vortec water pump and intake, the Vortec heads are a drop-on. You'll have to use a Vortec exhaust manifold and exhaust-to-intake tube to keep the EGR functional.

If you use the TBI water pump, you'll want to drill a hole in the Vortec head deck surface to align with the coolant bypass hole in the block. You'd only have to drill the head for the passenger side...but I'd drill both so it doesn't matter which head goes on the passenger side.

If you need the crank sensor, you'd have to swap timing covers, the reluctor on the crankshaft, and the torsional damper.

You'd have to make sure the pulleys of your accessory drive system aligned.

 

[Erik the Awful]

Some of the parts mismatches are outlined here:

How to Put a Vortec Motor in a TBI Truck

"Can I swap a Vortec motor in place of my TBI motor and does it just bolt in place?" Yes, you can swap a Vortec motor in place of a TBI motor, but no, it doesn't bolt in place. So, what does it take? Head and Intake Differences: The Vortec manifold has eight bolts, two on each corner, drilled...

www.gmt400.com

 

[GavinJansma]

If you use the Vortec water pump and intake, the Vortec heads are a drop-on. You'll have to use a Vortec exhaust manifold and exhaust-to-intake tube to keep the EGR functional.

If you use the TBI water pump, you'll want to drill a hole in the Vortec head deck surface to align with the coolant bypass hole in the block. You'd only have to drill the head for the passenger side...but I'd drill both so it doesn't matter which head goes on the passenger side.

If you need the crank sensor, you'd have to swap timing covers, the reluctor on the crankshaft, and the torsional damper.

You'd have to make sure the pulleys of your accessory drive system aligned.

Thanks

 

[1989GMCSIERRA]

You’ll probably lose the roller cam unless you drill the TBI block for the roller cam