Need some good advice on engine replacement

[woodrow59]

My '68 Longhorn has a TH400 which I'm guessing is original (don't know for sure). Were the Longhorn transmissions different or just the drive shaft ????

Previous owner put in a '85 305 which is gettin' ready to bite the dust. Been lookin' around for old cars for a donor engine (cheap) .
What will bolt up to that TH400??? Will all Chevy SB's bolt up? How 'bout Olds or Pontiac ??

I have limited funds so I need to find a cheap way to replace the engine. My mechanical skills are above average (I have rebuilt a carb, replaced everything on the outside of a motor and fix anything around the house that my better half says needs fixing LOLOL)

But,,,,,I have never replaced a motor. I know I can do it,,,,,,,,I just need to know what will bolt up to that TH400 without any modificactions.

[Longhorn Man]

Asuming it is the origianl TH400, any Chevy engine you would want to put in there will bolt up. The 2.5 inline four,a long with what ever four was in the first gen Nova...any gasoline inline 6, all small blocks, all big blocks.
non chevy engines will not bolt on wihout an adapter. BOP bellhousings,(stands for Buick Olds Pontiac) was used on all other GM names...including Caddy engines.
Both the longhorns I have had TH350s in them by the time I got them, but I am unaware of anything special on the stock ones. It was a normal slip yolk wasn't it?

[woodrow59]

By slip yolk I'm guessing you mean 2 piece drive shaft ??????

I've replaced the front U-joint 2 times. First time with one from "Parts Are Cheap".... next time went to NAPA with the measurements from the U-joint ......they found what they called a "bastard joint" that was often used in Hot Rods. It kinda fit (had to do some "shade tree engineering") to make it fit just right.

Just a question,,,,,,why did yours have TH350's in them by the time you got them ?????? Replaced????? Why ??????? Is this TH 400 a piece of dutttty? (being kind for the kids that I'm sure get on here)

[Longhorn Man]

by slip yolk, I mean a very short (3 -5 inch) shaft that slides into the tranny over a male splined shaft in the tranny's tail shaft, and not they style that bolts to the tranny like some of the 4 speed trannys of vintage years (Like some of our 4 sppeds I think) I might be able to find a pic on my puter or take one tonight at home.
As for why my trucks had TH350s...I have no idea.
The first truck seemed all original ('all' used loosly). It had a short shaft Th350 with a brokem bellhousing. The short shaft is correct for these years. That and the fact that the drive shaft did not look modified,a nd the fact that the original owner's widow did not remember ever having the tranny replaced made me think it was original. I later found out that Longhorns could only be had with a TH400 if you wanted an automatic...
Even so, i still get the feeling that it was origianl...just looked to 'right'. There were other parts on that truck that did not belong there...like a silver and black inst panel instead of chrome and black. That shoulda been a '67 item only. Another one that the wodow lady said was there originally to the best of her knowledge.
The current Longhorn had a Pontiac 350 and TH 350...with that kind of swap, anything goes.
Kinda like the caddy engine now in there....anything goes.

[crazy longhorn]

"quote".... is a 400 turbo a pc of duttty? No man! that is the best hydro that GM put out. My longhorn had the original, (I think).....at any rate, with 140+ on the clock, & a d@mn tired 350 she would still bark rubber pulling 2nd gear. They are good for about a 1/4 million miles, if properly maintained! my longhorn had a slip yolk in the trans, & also at the middle of the shaft......still the same, but the front slip yolk is in a 6spd Richmond(yehaw!) crazyL