1978 327 swap into a 1998 z71

[Chrisparsonsracing]

Ok so to keep it short I have a 1978 4x4 with no body and a 1998 z71 with a blown engine I am taking the existing 5.3 out of the Z and replacing it with the 327 from the 78. I know it will bolt up and run in my truck but will the trans and transfer case still work behind the 327 straight wired into the truck. I also need to know if it's best to put my 98 distributor into the old 327 or do I need to leave whats there in there 

[CamGTP]

What are you going to do about the EFI?

 

Did you mis-type and mean 1999?? Because the 5.3 wasn't an engine option until the NBS 1999 model year trucks.

 

The transmission and transfer case will not work anymore because the transmission is controlled by the computer and that 1978 engine uses a carb. If the transfer case is electronic, that won't function either.

 

 

You'd need to install a TH350 or an early 700R4 with a kickdown cable for the transmission and use a different manual transfer case.

[Chrisparsonsracing]

So the computer will still be hooked up to the 12 volt system the engine will code out but will not effect the trans or transfer case my 5.3 distributor is going in the 327 and as far as the truck goes it was put into the truck before I bought it the efi is part of the ecm so it will just code out I just need to know what to do about the return lines on the tank and if the thumper on the 327 will pull fuel thru the in tank pump if its shut off 

Edited September 22, 2020 by Chrisparsonsracing

[Chrisparsonsracing]

Also I found out it was a 5.3 when I replaced the head gaskets the heads had relief ports in the center and no 350 gaskets had them the only ones that did were the gaskets for a 5.3 vortec also the big vortec cover on top was a dead giveaway the engine had been swapped prior to my ownership

[CamGTP]

It's not a 5.3 if it has a distributor, it's a 5.7.

 

There is a big difference between the carb/TBI 350's and the Vortec 350's that came in 1996-1999 OBS trucks.

 

This is a Vortec 5.7 350 engine.