My 1998 Chevy Cheyenne 4x4 4.3 liter V6 engine blew and I would like to know how hard it would be to put a 305 engine in it (I.e. will the 305 mount to the stock transmission, what other factors might I run into)?

there are a few things to consider , you'll need a larger radiator , engine wire harness for a v8 , computer, tranny, driveshaft ,exhaust manifolds,motor mounts, it would be cheaper to just buy one.

Ok, first off the 4.3 shares the same bellhousing as any small block chevy so the only conversion factors are the motor mounts need moved and the v8 harness. The trans you have assuming its automatic is an electronically controled 4l60e. The v8's share it. It needs the computer to work. A vortec 305 or 350 with harness and PCM will work best. Snag the radiator out of a truck with the v8. Be sure to get a 4x4 oil pan for your swap, there is a differance as the 2wd pan will contact the front diff. I dont sugest going carburated becasue of the trans needing a computer and a carb'ed 305 isn't really an upgrade over a vortec 4.3. Unless it's built out.

Just an afterthought, a 5.3 from the newer trucks will give you the best bang for our buck with just about the same difficulty. They even use the same tranny, would suggest a driveshaft upgrade.

Thanks for the quick replies. However, after speaking to a local mechanic who told me unless I have 6 months to wire in the new computer it definitely isn't worth the trouble. So, I'm just going to replace the 4.3 liter engine and get another transmission for it later down the line. Again, thank you for your input and time.

Sorry, also forgot to include the transmission is a 5 speed manual.

The 5 speed will handle a v8 and actually makes it easier. You mechanic is a pansy. Lol.