93 TBI To 97 Vortec

[Verm]

I have a 97 Chevy 1500 It has the vortec 5.7L in it and I have a 93 GMC 1500 5.7 Motor in my garage that i was gonna use the block from to build a motor for my 97. I know i need to change the heads, Intake, timing chain and cover. I wanted to get a cam for it but i have read online that the pistons and cams are different in those blocks and was wondering if when looking for said cam i should look for the kit for a 97 or a 93? As well as do i need to change the pistons. This is my first engine build I wanna be sure I'm doing everything properly and build it to the best of my abilities. Also any cam recommendations would be great!

 

[Moofus02]

If the 93 motor is set up with roller cam provisions you will be able to use it. If it's not drilled you can still use it but with a flat tappet cam. If I was buying pistons I would put flat tops in it. I can't see a reason that you would need to change pistons to do the swap. If the motor runs swap the vortec heads timing set with crank reluctor and balancer. I would use a holley timing cover instead of the plastic one.

 

[Erik the Awful]

You can modify a non-roller block to run the roller cam. I would rather do that than run a flat-tappet cam.

I wouldn't replace the pistons unless there was damage to the existing pistons. Flat tops will put you around 9.7:1, and depending on the cam you might have to start running 91 octane. Plus, you really need to have a machinist measure the pistons and cylinders to ensure your clearances are right - I bought .030" over pistons a while back, and the machinist had to bore the block a little larger than normal because the pistons were exactly 4.030" which put them in interference with a normal .030" overbore. That meant that the piston rings now have a larger than normal end gap. They're on the wide end of what you would want on a nitrous motor, but definitely streetable.

Also any cam recommendations would be great!

Call your favorite cam company. They can give you a better recommendation than us random internet weirdos. They'll actually ask you questions about what you have done to the truck and what your expectations are.

Inspect your heads carefully while they're off. In fact, I recommend sending them to a machine shop for vatting and magnafluxing. Most Vortec heads are cracked.