will a 92 F150 HO bottom end swap in my 91 merc?

[merc91]

have been going like crazy on this car and got it dynod and she puts out about 300hp and 350ft/lbs at the flywheel and am in the mid 14's in the quarter at 93mph... then i put in a nitrous system in the old girl and its time to swap out the stock bottom end before i go flicking on that switch.

so just seeing if the block and rest of the bottom end will swap in fine under my current GT40P setup.

thanks, andy

[86VickyLX]

92 F150 is lopo as far as I am aware. You want forged internals. I want to see videos of this car mang!!!

[gadget73]

the truck bottom ends are odd. They're usually flat tappet with goofy dished cast pistons. Not useful, you want a Mark VII or Mustang bottom end for the good internals.

[1980c10]

90-92 mustangs got forged pistons

[zoomie]

i know of several mustang that run nitrous with HO stock bottom end case in point here is an excellent example

[1980c10]

I ran several bottles through my old 90 gt with 125hp shot and it never even flinched, I have also seen up to 175hp on a stock 90-92 bottom end without problems. Like any other power adder its all in a good tune.

[gadget73]

87-93 Mustang, 88-92 Mark VII are forged. 86 Mustang and 86-87 Mark LSC are also forged, but they have flat top pistons with no valve reliefs. 94-95 Mustang are hyper pistons which are usually fine for under a 200 shot, ditto with Explorer bottom ends. I think the 91-93 Tbird/Couger HO motor is also hyper, but its possible those are actually forged. Mark VII motors are usually the most available, and are often better cared for.

[merc91]

this motor has forged pistons and is a roller motor and a real ho. its been rebuilt with arp rod bolts and some other little things and the block freshened up. just want to make sure the block is the same with coolent passages and mounting stuff so i can just swap bottom ends. ill be doing this within a month and spraying some solid nos on top of the motor as is... going to get a hardened input shaft for the tranny to. that just slides out and put in the new one right?

[zoomie]

yea gods that cam and nitrous..... no tires left for you, rofl i imagine its going to be a beast!

[Grand Marquis GT]

I don't see the problem, but I'd still make sure to do the play-doh test just to be sure.

[86VickyLX]

When you put it that way. Yeah. The blocks are pretty much the same by means of the block castings.

[gadget73]

if you know what internals it has, then go for it. Yes, the block itself is physically identical, all mounts and passages, etc are the same. The only difference with some of the truck blocks is that they have a boss for a knock sensor where the bellhouse goes. This affects nothing as far as you're concerned tho.

Just confirm what the imbalance is. If its a roller block, it should be new enough to be 50oz, but make sure someone didn't do different stuff to the bottom end.

[merc91]

ok right on. i'm going to snag it. its got the same forged pistons and rods and crank as a HO stang, arp rod bolts, block machined, new bearings and rings and rods and crank are new to. engine has 25k miles on it so its at least been tested out good and broken in. should have it in the merc in a month or so, than get the dyno tune tweeked with it all, and likely a 125hp shot of nitrous then i'll be right down to the drag strip.