One is in a '81 RV and the other is in a '91 suburban. Both can be heard running. The '91 has less miles, throttle body, auto trans (not sure which one) and will lay a patch forty yards long. The RV motor doesn't seem as strong and has a T400 w/ trans. brake which I'm not sure if I can use. Both owners are wanting $700 for the M/T combo. I'm going through which ever motor I buy, so I guess it comes down to casting numbers I guess. Thanks in advance for the input.

I don't believe the 1991 models have a provision for a mechanical fuel pump. The 1981 454 will.

I think both will have peanut oval ports

454's out of r.v's usally have steel cranks in them...

buy both : )

Do you now any casting numbers for either block, or the heads? That would help with the advice you'll get. It sounds like you plan on tearing it down and rebuilding it, so I wouldn't worry about the miles too much.

Which owner do you like better?;)

The 91 will have the fuel pump provision. They both will most likely have the peanuts but that isn`t nessasarily a bad thing. Have you checked craigslist for a caore? I see them all the time for around $200 for a 454 core and about the same or less for a th400 core.

Isn't a 1991 engine a Mark Five?

91 was the break year - it could have either a Mark IV or Gen 5. I'd opt for the Mark IV, the Gen 5 is the bastard child with no fuel pump boss and it'll take specific gaskets to use older heads. Even then, it's a crap shoot. Get the casting numbers, they will make the difference - or they would to me anyway.

91 was the break year - it could have either a Mark IV or Gen 5. I'd opt for the Mark IV, the Gen 5 is the bastard child with no fuel pump boss and it'll take specific gaskets to use older heads. Even then, it's a crap shoot. Get the casting numbers, they will make the difference - or they would to me anyway.

So if the '91 has no fuel pump boss, it's a gen 5 and the '81 would be better?

So if the '91 has no fuel pump boss, it's a gen 5 and the '81 would be better?

Pretty much.:yes:

I went and looked at the '91 again. I could not get to the casting number, so:confused:. I was able to locate the suffix code on the front though. It appears to be "UCH". Which from what I've found says '93 230 horse TBI. Also I'm not real familiar with BB's so I'm guessing the fuel pump boss is in the same location as SB's and there isn't one. These two seem to point towards being a gen. 5. The '81 suffix code is "TRM" which is 250 horse truck. I do not have the casting number off it due to it being an hour drive away. Basically I only need the block, crank and rods, so the '81 may be the way to go. Or maybe the core thing is it. I may be giving too much for no more than I'm going to use.

that's not a trans brake. that's the parking brake for the motor home.

get the 81.

$700 for a complete and running 454 that comes with a transmission is a pretty good deal. Besides, one can never have too many parts.:)

Buy the 81 454 engine and tranny and go! And right it should have a drum brake on the end of the tranny if not mistaken????

Kinda like a flat wheel w/ an auto tranny band around it and a toggle like an Orscheln Brake Lever e-brake set-up off a fork truck.

pdq67

I've talked the '81 owner down to $600 for the combo.:beers: I've thought about the core thing, but all the brackets, pulleys, flywheel, etc. will definately make it worth while.