351w/4r70/atlas clearance with JDuff arm

[NM_outdoors]

This setup is being installed in my '70 project and I need some suggestions on a clearance issue between the Atlas II and the JDuff radius arm bracket. I'm thinking about shifting the drivetrain toward the passenger side of the vehicle about 3/4". To do this I would slot the 4 (block-mounting) holes in the engine mount. Maybe leave the front drivers side mounting hole as a pivot point and slot the other 3 as needed. Since the clearance needed is almost 40" from the pivot, the holes wouldn't need to be slotted too much (1/8-3/16"?). My biggest concern with this is clearance on the passenger side with the starter and exhaust (headers?). Also, prior to tearing this rig down to the frame, there wasn't much clearance between the firewall and valve covers. I'm going with a 2" body lift so I don't expect that to be a problem anymore. But with the drivetrain shift..... Who knows! The body is off and I'm thinking about building an adjustable-height crossmember for any fine tuning of install. Any suggestions on gaining clearance between T-case and the frame? If I do shift/pivot, can anyone tell me what the best header would be for clearance?
Here are a few pics to help visualize......

 

[NM_outdoors]

Side view of clearance. It's all sitting higher than final but I don't know what the final should be. In this photo, I have a piece of 2" angle across the frame rails so the trans mounting surface is sitting about 1.4" inches above the top of the frame. Anyone out there with a similar install want to give me the distance from the trans mounting surface to the top (or bottom?) of frame?

 

[NM_outdoors]

another view from the passenger's side with temporary 2" angle support.

 

[tatersalad]

Can't you just weld in the duff radius brackets to eliminate the bolt that goes through the frame and leave it where it sits.

 

[tatersalad]

I only run a d20, but I think you might have the atlas sitting up to high also.

 

[tatersalad]

Re

Here's a pic of my d20

 

[NM_outdoors]

Thanks tatersalad. Yes, it's probably about 4" high as it sits in the pic. By the time I lower it to final height it's damn close to the hiem bolt head. Yes I could live without the bracket bolts but I can't live without the hiem bolt that acts as a pivot for the arm. I could bevel the head at one of the flats (as suggested by my 16 yr. old son) but, under flex when wheeling, I'd still like a little more clearance.

 

[mgb0302]

Just wondering what you finally did. I am in the process of purchasing a 4r70w and want to get an atlas as well. I have the duff long arms and don't want to run into any issues.

Thanks,
Mike

 

[KyleQ]

Put the bolt in from the other side, trim to fit. My Atlas is super close to the frame and bolts and yet hasn't made contact with it yet.

 

[NM_outdoors]

What KyleQ said.... ^^^^.