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 😉

 

what state ? Do you have to smog test this beast ?

 

I live on the coast of Washington state and so no we don’t have smog test out here, I’ve already gotten rid of all that on it anyway

 

Try the engine specific forum also - https://www.ford-trucks.com/forums/forum53/

Sixto
07 E350 5.4 183K miles

 

Thanks I’ll do that

 

no smog helps , I will share that if you want to change performance instantly , put a 429 Cobra Jet lower crank gear on ( for the timing chain ) it will wake that thing way up . Of course full dual exhaust ( with a crossover ) will also help , can’t go too big on the radiator, and a good quality fan clutch

 

I will check out the lower timing gear, I was thinking of putting on a comp cams true roller chain and gears and as for exhaust I am not able to run dual exhaust because I have a hydraulic system between the transmission and frame on the drivers side but I have removed the cat and am running 3” pipe from the Y with a straight through muffler

 

For durability, I would add ARP rod bolts, and ARP main and head bolts. To get really tough I'd stud the mains. Head studs are better than bolts, but you'll have trouble if you ever need to pull the heads on a van (with head studs).

I have twisted oil pump drives using a high-volume pump and heavy oil, Ford performance makes a nice heavy-duty piece.

I suggest balancing it any time you make changes in the rotating/reciprocating assembly.

I second the 429 CJ timing gear.

Pay attention to your fan shroud, it will help get the most out of your radiator.

I busted a lot of flex fans on my mud truck, never had any problems with a good clutch fan.

 

Thanks, I plan on using ARP bolts on the head and rods and an ARP oil pump shaft as well even though it will only be turning 4,500 max and even that won’t be very often

 

I'm old fashioned in my reasoning but my theory is if too lean we'll burn holes in pistons.
So, therefore if i'm running a little rich on those hot 110 degree days a working a long grade with pedal to the floor maybe my engine will run cool (er).
Above of course thinking carbureted engine.

Your '88 is probably fuel injected so no air / fuel adjustment available.
A thought is maybe add some Marvel mystery oil or even some ATF to slow the burn rate ?

Your engine could have experienced an intake air leak on the one cylinder which got so lean and hot it burned the hole in the piston, while all others are fine.