Brain Teaser

I am putting in a Chevy 350/t15/dana20 combo onto my '69 CJ5. The jack stands are under the axles, and the frame is level. The frame is attached to the leaf springs, I haven't attached the shocks yet, and I am currently looking for a place to put the engine. As the rig sits right now, the rear differential u-joint is 11.5 inches off the ground, the bottom of the rear cross member is 12 inches off the ground, the top of the cross member is 13.5 inches, and the transfer case u-joint is 20.5 inches off the ground! Even I realize 9 inches is just a tad too much of a difference. My question, before I start figuring out how to drop the cross member is how much vertical relief can I expect once the shocks and body are attached? I would hate to drop it too low only to have to reverse what I had done once it is complete. Thanks for loaning me your brains!!

 

have a couple people stand on it

 

Ya might want to temporarily set the tub on there to see how far forward you need to set the engine/trann/tc in order for the body to fit properly, which may help on your placement of the height, also.

 

This.
You will probably need to angle the pinion up on the rear diff also. If those are new springs they will settle some, plus the engine and transmission needs angled back (transfer case down). Iirc it's about 4*. Put a level or angle finder on the carb/air inlet on the intake manifold. That portion should be level side to side and front to back or you can angle it back somewhat also if needs be.

 

You could weigh everything that is not on the chassis yet. Tally up the capacity of your gas tank and convert that gallons figure to pounds and then buy a few sand bags to equal the estimated weight of all missing parts and lay them on the frame rails centered about where the driver's seat will be.

 

set the tub on it especially if you havent checked for clearances motor against firewall, shifter placement, etc.

 

Thanks for the great replies. I am buying a new tub and don't have one to work with right now. I do have the grill however. On this year group CJ, how far is it from the fan shroud to the firewall?

 

Right now it looks as if you have no spacers under the crossmember, there should be at least 3/4" under it from the factory if a t14/t15 is used.
I also agree, you will need a body before you mount any of that permanent!

 

The crossmember in the photo was bolted directly to the frame. When I got the Jeep the PO had a 3.5 inch spacer on one side and direct to the frame on the other. I probably will manufacture another spacer for the other side to lower the angle some. On a related note, how much angle on the rear diff is too much, if I remove and reweld the spring supports? From what I have read Dana recommends a level diff and a level transfer case, but if the engine is angled 3-5 degrees there is no way to keep the tc level. It would appear as well that the crossmember sits too high anyway, the bottom of the crossmember is .5 inch higher than the u-joint on the diff. Sorry to beat this thing, but I just do not understand how the angle between the two could ever be 3-5 degrees and both be level.

 

Most vehicles, Jeeps Included typically come from the factory with the trams and transfer case tilted down. Look at any sbc with the carb removed and check the angle of the carb mounting flange. To level that, which is important, you have to angle the engine back. Most other engines are the same. You need to mount the engine, trans, and transfer case in such a way to have clearance between fan and radiator, exhaust, steering, and front and rear propeller shaft angles. There is always a compromise when a conversion like this is done. There are no hard and fast measurements as each conversion comes out slightly different. Again, you may have to angle the rear pinion upward as well. Wait until you have a tub to sit on the frame, and invest in an angle finder to help you set things in place. If you don't you most likely will have issues down the road unless you get very, very lucky.


Sent from my iPhone using Tapatalk

 

Great web site Lynn for reference.

From that site.

 

Sweet! just what i needed, thanks fellows!