Hi i own 56 f100, this is my first restoration. I have the whole truck apart to start from the bigining. Im working on the frame sending cleaning etc. The 272 v8 engine is still mounted on the frame. I want to keep the original engine because im going back to original with little few changes. Engine runs drove the truck few blocks when i got it runs good no wired noises very good my opinion. Messured pressure in every single cylinder pretty even 120 all of them except cylinder 5 red 100. My plan was just to replace seals, gaskets, pumps, and some other parts, but i would like to hear some advice from you guys . I want to know if there a way to make sure if engine needs to be rebuilt . tHANKS FOR YOUR TIME GUYS

 

I would measure cylinder taper/wear. If tolerable do a quick ball hone and get some new cast rings.
Check main and rod bearing clearance with plastigauge. I think the max limit is .003. If it is over that have the crank ground and get new bearings.
Regrind valves and replace if needed. New valve seals come with the gasket set. For a stock low performance engine my opinion is that hardened exhaust seats are not necessary.
Replace valve springs if they are weak. Have cam reground along with lifters to stock specs. New timing chain and gears.
This is BARE BONES, not rebuild. But if the cylinders are ok, maybe you can get it done relatively inexpensively.

 

JMHO, but if I had the time and funds I would go thru the engine now. If the compression test was done correctly, those are not very good numbers. I was faced with a similar thing you are when I started my current '56 project work truck. The virgin 272 ran ok, great oil pressure, power, etc, the PO had been using it. I looked at the maint. records that were with the truck. I pulled valve covers to adjust valves and found oiling to the rockers was not what I thought it should be so I pulled the heads. I wound up finding a cracked head that had been allowing coolant into #7 cylinder for a long time. #7 also had a cracked piston, probably from hydrolock at one time. Closer reading of maint. records substantiated this truck had had coolant disappearing for a long time, like since new. The fix had been to throw stop leak at the problem. Any way, I wound up boring .040" to clean up #7 cylinder. The other cylinders were not worn badly at all. The cam showed wear so it and lifters were replaced. Amazing,the crank polished and I went back with std bearings. The rocker assemblies and valves were in good shape.
Your truck, your call. It sure is easy to pull an engine when the sheet metal is not in the way.