[Tom63LeMans]

Originally Posted by Joog

Thanks! Did you copy that design from the HAMB? I'm also doing a gasser build. And I think I saw your 56 at Pontiac nationals.

Yes that’s me. I used the Hamb post for some of the measurements and the basic idea. I didn’t care for how far forward the mounts were from the engine bolts but understood it was done that way to reach the original crossmember. I originally was not going to add a mid plate so I was concerned about stress on the bellhousing. I did end up adding a mid plate too.

[Joog]

Originally Posted by Tom63LeMans

Yes that’s me. I used the Hamb post for some of the measurements and the basic idea. I didn’t care for how far forward the mounts were from the engine bolts but understood it was done that way to reach the original crossmember. I originally was not going to add a mid plate so I was concerned about stress on the bellhousing. I did end up adding a mid plate too.

Alright, do you by chance have a photo of where and how you connected the bracket to the frame? And possibly a picture of the midplate.

[Tom63LeMans]

Originally Posted by Joog

Alright, do you by chance have a photo of where and how you connected the bracket to the frame? And possibly a picture of the midplate.

Here are a few pictures showing crossmember and brackets for the motor mounts and midplate I used the Speedway biscuit motor mounts but then used aluminum spacers in place of the rubber mounts. With the mounts moved back like I did I might have been ok without the midplate but didn’t want to chance it. I also found a few pictures of my rear crossmember if you’re interested.

[Joog]

Originally Posted by Tom63LeMans

Here are a few pictures showing crossmember and brackets for the motor mounts and midplate I used the Speedway biscuit motor mounts but then used aluminum spacers in place of the rubber mounts. With the mounts moved back like I did I might have been ok without the midplate but didn’t want to chance it. I also found a few pictures of my rear crossmember if you’re interested.

Thank you! If I understand this right, you just welded the bracket along the sides of the frame facing the motor, and maybe welded some on the bottom side of the frame?

[Tom63LeMans]

Originally Posted by Joog

Thank you! If I understand this right, you just welded the bracket along the sides of the frame facing the motor, and maybe welded some on the bottom side of the frame?

I went back and looked at the pictures and then recalled how big of a job it really was to patch the frame after removing the crossmember. I removed the complete crossmember where it was riveted to the frame rails. Then I plated the insides and also the bottom opening for the springs. The new crossmember is notched so it’s welded inside the rails and underneath like you mentioned. It was the new plates that strengthened what was left of the frame and gave me a good surface for attaching the cross rail for the motor mounts

[Joog]

Originally Posted by Tom63LeMans

I went back and looked at the pictures and then recalled how big of a job it really was to patch the frame after removing the crossmember. I removed the complete crossmember where it was riveted to the frame rails. Then I plated the insides and also the bottom opening for the springs. The new crossmember is notched so it’s welded inside the rails and underneath like you mentioned. It was the new plates that strengthened what was left of the frame and gave me a good surface for attaching the cross rail for the motor mounts

Thanks for the info! And I saw your headers, I'm guessing you custom made those yourself? I was thinking about trying to find SBC fenderwell headers and cutting the flange off, then bending the tubes and tweaking them to work with a 400 flange. Since I don't have the patience or skills to do a whole custom header myself.

[Tom63LeMans]

Originally Posted by Joog

Thanks for the info! And I saw your headers, I'm guessing you custom made those yourself? I was thinking about trying to find SBC fenderwell headers and cutting the flange off, then bending the tubes and tweaking them to work with a 400 flange. Since I don't have the patience or skills to do a whole custom header myself.

I used BBC Patriot headers for tri-5 Chevies to build mine. I think they are 2” primary tubes. That worked great for these since I’m running round port Edelbrock heads. If D-ports and not heavily ported SBC 1-3/4 tubes should work. Since I kept my original steering box and location the upward turns have to happen quickly.

[Joog]

Originally Posted by Tom63LeMans

Here are a few pictures showing crossmember and brackets for the motor mounts and midplate I used the Speedway biscuit motor mounts but then used aluminum spacers in place of the rubber mounts. With the mounts moved back like I did I might have been ok without the midplate but didn’t want to chance it. I also found a few pictures of my rear crossmember if you’re interested.

Can you get away with doing only the front motor mounts and the rear crossmember? Or do you also have to do the mid plate. I won’t be making that much power, probably if I’m lucky 425 hp. I’m going to be running a Th400 trans

[Tom63LeMans]

Originally Posted by Joog

Can you get away with doing only the front motor mounts and the rear crossmember? Or do you also have to do the mid plate. I won’t be making that much power, probably if I’m lucky 425 hp. I’m going to be running a Th400 trans

For lower HP and mainly street driven a mid plate should not be needed. I did it since I planned on running 10s and launching hard off a transbrake.

[Joog]

Originally Posted by Tom63LeMans

For lower HP and mainly street driven a mid plate should not be needed. I did it since I planned on running 10s and launching hard off a transbrake.

It'll be street and drag driven. Gasser. But I'm younger and don't have infinite money to build a 400, so I am hoping I can hit the 400hp mark with it. Guessing I won't need a mid plate?