mn1500

I have a 74 Chevy 3/4 ton two wheel drive pickup and am looking to replace the older motor with a newer version 350. I like the one piece rear main seal and have read that the 96-99 5.7 Vortec motors have some real good flowing heads and make some good power with valve seats that can run unleaded gas. I would like to keep a carbureted motor so I am just looking for a long block. I see lots of motors on CL and have noticed a few come up advertised with the same problem. The problem I am seeing is low compression in one or more cylinders. They state the motors run but have low compression. Is this a common problem with this motor and if so what is the problem? How much damage has been done to these low compression motors? I dont want to buy something that is know for cracking heads and have to buy more heads to complete my conversion. I am also aware this is not enough information to diagnose a motor problem, I am simply asking if these 96-99 5.7 vortec motors have some known engine issues or if these are good donor transplant motors, and why a low compression issue?
Thanks,
Mike

gamble686

iTrader: (3)

I would stay away from those years in general. They did have some very odd issues and have an extremely limited aftermarket support.

mn1500

Anyone know about the low compression problems with these motors? Also not sure on limited aftermarket supply. Since I want to use a carburetor all I need is a intake manifold and then select a cam, seems simple for the old 74 3/4 ton. Any additional advice on what the compression problems may be, or how the heads for thes 96-99 motors stand up?
Thanks again