I want to replace my 318 with 400,000 miles with a 360. what problems will I encounter?
Thanks

 

What year is your truck?

Manual or auto trans?

 

2001 and auto trans

 

Any 360 out of a 96 and up truck with auto trans will drop right in. You MUST use the flex plate from the 360.

Various sensors/connectors changed over the years, so, put your intake off the 318 on the new motor, and that takes care of the majority of them. Crank sensor will be the other one.

You can have your PCM reflashed for the 360, if you can find a dealer that will do it.... or, you can get a tuner from hemifever, just let 'im know what ya got. He is out of the actual tuners at the moment, waiting for the new version to come out...... not sure when that's gonna happen... shouldn't be real long though.

Or, you can run on the 318 tune.... but, you will tend to run lean in open loop. (cold engine, and/or large throttle openings) Could be bad......

 

While you're dropping a 360 in, freshen it up, replace the heads, replace the plenum, do a kegger mod, etc.

If you treat the 360 the way you did the 318, everything should be good for at least another 200k.