high mile short block check?

i am going to look at and hopefully buy a 94 360 magnum motor and tranny combo for my truck project thursday. My plan is to hopefully be able to keep the short block stock and have the heads reworked and add a intake and cam. Is there anyway to check over the short block internals for wear? i am gonna try and get the guy to do a compression check on it before he pulls it. I have test indicators and telescopic gauges and calipers, gonna check the bore size and crank endplay, is there other checks i can do to see how solid the bottom end is? The motor has about 100,000 miles on it and ran off propane alot of its life, any help or suggestions would be great.

Take a look at the cylinders for crosshatching(should still see alot of it), uniformity of the cylinders and should have a nice smooth feel all the way around. And pull the pan at least to check a few bearings. If the spark plugs are still in it see if they all look alike.

I just went through this with a 1999 5.9 from an Dakota R/T. There were 135 kilometers on the motor.

Since the magnum came out of a R/T, I felt it got beat on regularly. The upper shell of the rod bearings were starting to show wear. Replacing them was easy, just take your time and don't knick the crank. Visually inspect and 'feel' the surfaces after cleaning things up. Use assembly lube, verify the fit visually and by feel. Use a good torque wrench that you trust. You can change 2 sets at a time. The pistons push into the bore easy, and you can get some sort of look at the bore finish (but not at the critical ring area). The cross hatching still looked good with very minor light scratching that the fingers could not feel.

The lower shell of the main looked good, the upper? I didn't care to lift the crank.

I made a baffle for the car oil pan, cut down the oil dip stick tube, and made sure it fit through the baffle.

The valve seals look like quality viton seals. The engine in general looked sludge free with a fair amount of coking.

I have MP valve covers for it and a crosswinds intake. I also added the timing chain tensioner.

If my computer program is as accurate about the engine output as it has been with other 'builds', this should be a very competent driver in my Challenger. There is no point in using a tired, mild 440 when the output of a healthy magnum is about par in torque and hp. The program shows mid 12's possible, so a high 12 to low 13 is fine with me as a driver.

As you know propane is very kind to bores. the crank/bearings condition would depend alot on how often he changed oil/filter. 100K is ALOT of miles & I would pull several main/rod caps & see what you see. EDIT but with the shortblock out & on a stand it'd be real easy(& cheap) to rering/bearing it & only slightly more effort from there to rebore but you know where you are at with that.

i guess i will just have to wait and see when i open it up. I have never done this type of checks on an engine, but i feel that i could if i had a good shop manual for reference of torque specs and assembly notes. If i decided to re-ring the engine and the bores were in good shape, how much more work would it be to change the pistons to some KB's for a comp increase? again i have never have done this before so i dont know what is required for the install . thanks

Before you tear it down do a leakdown check. You will know how good the ring seal is !

i think i am going to build my own leak down tester at work next week, it looks easy to do

that'd be a good plan to check compression/leakdown & post your findings & price a set of KB pistons/rings/bearings/gaskets & your machine shops price to bore/hone/cam bearings & see if that is going to be inside your budget. what are your plans for it, daily driver, street,street/strip & what octane.

my plan is just to have a street machine and track it a few times a year, i would set it up for 91 cuz thats what around here. I was thinking the KB 107's but if its going to be hard to get it to run for a newbie with that much comp i might go with something else. I am not sure sure on my budget yet either, gotta see what works like before i spend a pile of money.