I have a 1988 class c motorhome and I am going to build a 460 short block , I picked up a 1990 short block with unknown miles to have bored , I plan on putting in forged pistons , it has the original front balance weight but didn’t come with the flex plate , the engine in my motorhome is a 1991-93 I think , first question is can I use the flex plate off the 91-93 ? And by using forged pistons do I need to have the whole rotating assembly balanced ? I won’t be turning over 4000 rpms as it’s a RV , I’m using forged pistons to make my bottom end extra tough because I recently went on a trip and was going up a bunch of steep hills in 110 degree temps and melted a hole in a piston with no pinging before it happened so I had to have a shop in the area I broke down in put in the used newer engine to get me home as I didn’t have time to have a rebuilt engine done so that’s the reason I want the forged pistons so the engine can take the extra abuse of having to always be hauling around 10,000-12,000 lbs including pulling my Jeep and I am going to put in other performance parts such as comp cams 4x4 cam, so what does the Ford guys hive mind know to help me , thanks guys 😉

 

I'm running a balanced 460 in my E250 Ford Van used for towing.
My recommendation is to have the rotating assembly balanced just for insurance.

You might try adding some lube to your fuel when you know you'll be working that engine. I add Marvel Mystery oil to my fuel. (atf is ok too or 2 stroke oil).
Also, You might consider finding someone who can check your fuel to air ratio at working temps.
When the engine runs lean on a hard pull, a result can be burned holes in pistons, which I've encountered.