This may have already been answered here but my connection is way too slow to find it. My question is - can I replace the plastic intake manifold with the older style aluminum one? It would seem to be the way to go to avoid future leaks? What'* the problem with doing this? Thanks

on the 92 3800 the alum. intake was used, there was also no EGR valve on the 92 engine. on the 93 and later 3800 was the use of the EGR and the composite intake. the EGR stove pipe comes through the botton of the intake. There are much less, failures of the Series One Intake than the Series Two

so because of the Stove Pipe the 92 alum intake cannot be used

You can use the new aluminum upper (2004) and up, about $130 from Gmpartsdirect, but that one requires an adapter to use a different throttle body.

See the several threads here for some thoughts on repairing the plastic manifolds.

well we are talking 2 different things here....the Series One used the Alum intake in 92 and that was the EGRless engine, the 93-94 Series One used the composite intake, and have no problems. Series Two has the crappy Composite intake that is prone to leaking, and the Series Three has the Alum Intake. the Series Three can be used on the Series Two with a TB adapter plate. the 92 Series One Alum intake cannot be used on the 93-94 Series one

I'm not sure what engine redblur has in his car....I am assuming a Series One, so the Series Three intake would not work, he is stuck with the Composite, but they do not have problems like the Series Two

I have a 98 bonneville with the series 2 3.8L vin K. That motor has crapped the bed with it'* spun rod bearing - probably due to that intake failure I've heard so much about. I just bought a replacement engine for it out of a 02 bonneville w/ a little more than 50K on it. Are these 3.8 motors any better than their predecessors?
I have pulled one of these engines before out of a buick for a friend'* oldmobile 88 - it wasn't as fun as some others I've done, but not without it'* rewards. At least I have some experience and a little head'* up on some of the pitfalls. I hope eveything will fit together as nicely as I'm hoping. Thanks for all the help everyone. It should be running within a month - I'll keep you posted.

No difference between those motors. O2 sensors are though, so plan on keeping all your exhaust manifolds and sensors, as well as perhaps some bracketry for the accessories.

If that donor motor hasn't had the failure yet, watch it. GM made some improvements in the intake manifold, but we have had a couple newer manifolds give up too. Dorman makes probably the best alternative. I have yet to see one fail.