I have a 1985 empress 32 ft motorhome. I bought it and it overheated on my journey home. I bought a 454 bb engine because water is poring into the oil pan so I figure the block is cracked and ruined. The engine I bought is old. It is 1973 but was rebuilt in 1985. It was bored .030 and .010 on the bearings.. I am taking this engine apart. I have found the timing chain is totally sloppy it moves 11/2 inches. The bottom crank gear is worn badly. The piston heads look great. The piston chamber walls look fine. The ridge feels like about 2-3 thous only guessing though. I will be looking at the bearings tomorrow. Heres some of the potential problems.

1.My heads are oval port from this engine and are 781's. The intake manifold isnt the same as my 85 but I will need to use my 85 intake because it feeds air into the exhaust. However the 85 its intake manifold ports are smaller I believe they are called peanut. The question is can I use the 781 heads from my 73 engine with the 85 intake manifold.

2.Also I was told that my crank in the 85 is steel Will the cast crank in the 73 be ok in the motorhome. Will the crank from the 85 fit the 73 block(I gues not because the 73 is .010 over on the bearings)

3. I was told to check the cam I can measure the small dia and then the large diameter with a vernier and the difference will tell if the cam lobe is within spec. I dont have a dial gage.

4. If the cam is worn could I use the cam from my 85 motor if it is still in good shape?

I would like to get away with new rings possible bearings if needed. I have already recontioned the 781 heads. My brother has an edge reamer and a reamer to do the piston walls, and a ring cleaner just need a compressor.

Any insights much appreciated. Thanks