Junkyard engine advice

[ollopa]

I want to replace the blown engine in my daily driver but the car itself is not worth the price of an engine rebuild. I'll be getting a running junkyard engine with a 90 day warranty. I don't want to spend much money but I also don't want to waste a good opportunity while I have the engine on the engine stand. Should I just slap the new engine in as-is or would it be well worth the effort to visually inspect/plastigage/replace the rod and main bearings?

I have to remove the oil pan anyway (2.8L to 3.4L conversion) and I'm already planning to replace the oil pump.

Thanks in advance,
Ollopa

[bszopi]

What car/engine combo are we dealing with?

[ollopa]

OK the car is a '90 Trooper and I'm going to replace the blown (as in dead, not forced induction) 2.8L with a '94 or '95 3.4L from a v6 Camaro.

[3100 MPFI]

I always check things out. I bought a replacment 3.4 DOHC for my 1995 Cutlass Supreme that was suppose to be running, but when I was working on it, I noticed something wrong. Turns out it has a broken valve that punched holes in one of the pistons.

[ollopa]

Correct me if I'm wrong, but it seems like if I'm gonna check the bearings that I might as well just replace them. And if I'm going to replace them, then I should have the crank polished. I'm worried about one thing leading to another and the whole cost of the swap increasing. Are the main and rod bolts reusable after I inspect the bearings?

[SappySE107]

You could but check ebay for bearings. They are cheaper there if you can use the stock size bearings. 95 junkyard motor isn't something I would trust without inspection.

[sil]

if it were me, id plastiguge, if ok
visual inspecition of cyl/pistion via spark plug hole and an LED light on a wire int here.
compression check
have someone turn key while checking compression
or get a starter bumper thing (so you can check yourself) the valvetrain