Conversation Between ManfredVonRichtofen and Gary Lewis

Thanks! I think you'll love a ZF5.

Thanks for the help by the way. Your build is looking excellent!

Yeah, I'll probably have the guy get some plate it make it connect to stronger mounting points. Going to be a project but the ZF5 is well worth the effort I think.

Thought of this conversation today when a guy with a 302 and an NP435 couldn't get the tranny in reverse. Turned out his firewall is cracked and the clutch M/C is moving a bunch. As I said, it isn't the size of the tranny but the fact that the firewall wasn't designed for those fore/aft forces. Nor was yours. The plate for ours wraps around the corner a bit and ties into the tranny tunnel. That gives it a lot more strength fore/aft than just a flat plate.

Haha...yeah.

Yeah, looks like some reinforcements have to been done. I'm also probably going to do a hydroboost conversion too which also will give room for the master cylinder.

Having that name, surely you will understand "yein". I didn't have to initially because I used a mechanical linkage, but in the resto I'm going with a hydraulic linkage and will have to reinforce.

The deal is that these trucks' cabs were apparently designed for a mechanical linkage, which puts the force in the up/down plane where the firewall is strong. But, in '83 they converted to hydraulic, which puts the force in the fore/aft plane, and the cracks started. So Ford made a plate that bolted in and spread the load over a much larger area. So it isn't because of the size of the transmission but the fact that the later transmissions came with hydraulic linkage that causes the problem. But, they can be run with a mechanical linkage, as I did, and there isn't a problem.

Hey Gary, I don't know if I asked you or not about this issue with the ZF5... I don't know for sure if the firewalls were made thicker as the years progressed but I have the 79 Bronco I am planning to have the ZF5 put in. There has been issues with the firewall flexing with the clutch set up for these big block ZF5s. Did you have to weld a plate to the firewall to make it more stronger?