4.3 swap
 

So my 2001 blazer has a blown motor and I have a chance to get a motor out of a 2003 would this drop right in or would I have to change a bunch of stuff...thanx for any help

Perfect! Buy it! Just put the 2001 intake and exhaust manifolds on the 2003 engine (for the 2001 A.I.R. and EGR systems) - easy peasy! Use the good Felpro LIM gaskets, run the threads with a tap, use Teflon head bolt sealer, and use an inch-pound torque wrench when changing the intake - correct torque is critical. Repeat torque after sitting overnight. Leaking LIM gets coolant in the oil and will trash the bearings. You will also have to use the oil pan for either a 4WD Blazer or 2WD blazer, depending on your application. If they're both 4WDs or both 2WDs, then no oil pan switching. Finally, be aware that 2001 and 2003 should both have identical two-wire knock sensors by the distributor, but you may want to verify on your 2001 - it was first year for that (hole in the block for mounting is different).

p.s. don't try to take the EGR tube loose from the drivers side manifold on your 2001 (loose from intake is OK). Careful with this tube and don't bend or twist it.

Come back when ready to actually do things, and we will help walk you through the actual process of R&R. Warning - engine R&R in a 4WD Blazer is not for the impatient, and not for the faint of heart!

yes I found out when pulling my motor...I used to love doin stuff like this. But this was by far the worst motor to pull...thank you for the reply and I'll keep ya posted

Yeah, they definitely put the body on after the engine went into the chassis. It shows!