drive shaft for BBC converson

[into69z]

I have installed a 454 in my 69 truck with a turbo 400. I have a 3/4 ton camper special with a standard long bed. i am trying to connect the drive shaft and things don't seem to fit. Is the drive shaft length different for a big block install instead of the factory small block? what is the best solution for my situation? new drive shaft? cut mine down( how much?) thanks for any and all help. Steve

[chevy72blu]

If you used the factory mounting location (or at least near it) you shouldnt need a new shaft. If you moved the motor back too far, you may need to have your shaft cut down. I need a little more info to tell you whats wrong

[into69z]

great-I bought new BB engine towers and installed them in the 1st and 2nd frame holes (top of frame) and the bottom part of the bracket into the farthest back hole on the crossmember (under the engine). the trans crossmemeber was moved back 1 inch- the holes were in the frame from the factory and I guessed that was for locating the bb/setup. the truck was stock with a 350 and turbo 400. everything motor and trans seemed to fit when i moved the trans crossmember back, otherwise, the engine mounts didn't seem to mount correctly up front...does that make sense?

[Tx Firefighter]

You moved the engine back. If you moved it one inch, you'll need to shorten the front half of the driveshaft an inch to compensate.

[into69z]

ttt

[into69z]

is it possible to install the engine towers backwards? I mean the ones I haVE SAY RIGHT OR LEFT BUT IS THAT FROM THE FRONT OF THE ENGINE OR THE BACK OF THE ENGINE?

[BB70c10]

as far as i know,all parts listed as right or left as an option,are as viewed from the drivers seat(left being drivers side and rt being pass. side).Working at a dealership i've never seen it any different.if thats how they are, then they should be right.

[Yullose]

The only thing you should have changed is the engine mounts... and you probably could have gotten away with using the stock small block mounts.

Big Blocks and Small blocks share the EXACT same distance from the motor mounts to the bellhousing. In other words, the trans should have been left in the stock location. A big block will bolt-in the exact same place a small block comes out, provided there is ample oil pan clearence.

[Tx Firefighter]

Originally Posted by Yullose

The only thing you should have changed is the engine mounts... and you probably could have gotten away with using the stock small block mounts.

Big Blocks and Small blocks share the EXACT same distance from the motor mounts to the bellhousing. In other words, the trans should have been left in the stock location. A big block will bolt-in the exact same place a small block comes out, provided there is ample oil pan clearence.

This is technically true, but, he wanted to use his big block mounts. From the factory, GM moved the engine a bit forward in big block applications to ease firewall clearance. Since he used the big block mounts, everything shifted forward and he's having to compensate for that.

It's all a matter of how correct you want to do the installation. I've always done them factory correct details, which causes driveline modification versus a small block truck

[Yullose]

That's good to know, because I will be removing the 292/3spd shortly and replacing it with a 454/Glide.
I know the frame stands are different, but had no idea that GM actually moved the whole works forward as well.

[Tx Firefighter]

Just FYI man, those 292 frame stands you have are pretty valuable on the parts board here. A 292 uses a special right side stand that no other GM engine uses, including the other inline six engines.

[Yullose]

Originally Posted by Tx Firefighter

Just FYI man, those 292 frame stands you have are pretty valuable on the parts board here. A 292 uses a special right side stand that no other GM engine uses, including the other inline six engines.

Well... unfortunately I'm relatively new here, and not yet a subscriber... So it would probably be against the rules for me to mention that the complete driveline will be removed in the coming weeks... and that we'd be willing to give it to someone in exchange for some green colored paper.


That is, assuming we actually have a 292. It's been a LONG time since I've studied those old Chilton books.

Here's a pic of it... maybe you can tell me for sure what it is... I thought the valve covers were different between the 250 and 292 motors... the 292 being wide/flat on the intake side.

Dayum... here I go hijacking another thread. (My apologies to the original thread poster)

[Frizzle Fry]

If you do the Big Block Motor Mounts on the cheap as posted by TxF himself you might get the wiggle room you need. I followed that FAQ when I installed my 476 and it worked great. Thanks Tx!