I have a 1998 K1500 5.7. I love the 5.7 Vortec, and want to buy a suburban that has that motor. My question is, how long did GM use the 5.7/5.3 Vortec? And what motor replaced it and is it as dependable? . . . Should I look for an older Suburban 1997-1999, or get a newer one mid 2000'*.

1999 was the last year for a Suburban (Chevrolet and GMC) with a 5.7 Vortec. The 5.3 is what replaced it. The 5.7 in the 1999 was in 1996-1999 models. They had issues with intake manifold gaskets letting coolant into the crankcase, therefore they often had oil pressure issues as well.

If I were looking in the approximate range of model years that you are looking at, I'd choose the 5.3 nine times out of ten. I like the 5.7 just fine, but the 5.3 is a better engine. The 5.7 can be made better than GM did, but if it'* never been overhauled it has likely had intake manifold gaskets fail therefore coolant in oil therefore low oil pressure.

I have a 95 with just the 350 in it and its a hoss. Theres nothin that thing can't haul inside and out! My husband has the 99 2dr tahoe with the 5.7 vortec and he loves it so I'd say whether its a 350 or a 5.7 vortec they are both just as good. It all depends on your personal preference really.

Yep, they're good engines . . . until they get coolant in the crankcase. Even then they seem to work fine for a long time. I know some got lucky and never had the problem.

My 1999 Sub would pound the main bearings at every warm start after the first intake manifold gasket failure put coolant in the crankcase. It still drove fine otherwise, but had only about 3PSI of oil pressure when warmed up and idling. Bring it up to about 1,000RPM and the oil pressure would come up. Prior to the intake it had 40PSI+ all the time. Straight 50W seemed to help a little, but not enough to make up for the strained starting when cold so I never tried it again.

I have a mid-80'* 350 in my C30 and it has hauled all kinds of stuff, a lot of it over the Rockies and it has always had plenty of oil pressure. That engine has intake bolts halfway between the front and back of the intake. The version in my 1999 doesn't.

I think GM saved $0.69 on each vehicle by removing the bolts in the middle and created the problem at the same time. Same engine with the front-feeding throttle body in my 1995 B-body never had a problem, but that intake had some height to it therefore longitudinal strength therefore bolts on each end actually could hold the middle down.. My theory at least, but never heard of the intake-gasket issue on the LT1s in the B-bodies, F-bodies, or Corvettes.