Power Booster Conversion Help Please

[1970GranCoupeConvert]

I am really banging my head on this power brake conversion so I am asking for a life line from the pros...

The back story...the car is a 1970 Barracuda California ordered car built in Hamtramck September 1969 (if that matters). It was originally a manual 4 wheel drum car and in the past I converted it to a manual master cylinder and front disc / rear drums but now I am converting it to power brake booster.

I have tried two of the bolt on conversion kits that are available and the trouble I had was that the "Bendix Dual Diaphragm booster" is that it moved the master cylinder too far forward to the point where the master cylinder would conflict with the stock cruise control servo and same thing with the "Hemi" style kit that has a mounting bracket that was positioned between the firewall and the booster and this bracket moves the master cylinder up and forward and that also conflicted with the cruise control servo.

So I thought I would go with a stock-ish 1970 system sourced from Rock Auto and the parts look like the system in the service manual PY367 diagram above in this thread.

The 1970 power booster has a large diameter pushrod rubber bellow so I thought I could simply cut out the center hole of the original manual brake reinforcement bracket and it would be a "bolt on" deal...nope the studs of the booster will mate up with the holes on the reinforcement bracket except that the holes are not the same configuration as the firewall.

The first picture is the reinforcement bracket placed on the firewall...the picture is not the best however the two top row holes of the bracket slide over the two firewall studs and then the bottom four holes of the bracket and the firewall all line up...that is how the original manual master cylinder bolted on.

The second picture shows the reinforcement bracket placed over the studs on the booster...the two top studs of the booster will not fit on to the top row of holes of the bracket but will instead fit into the second row bolt holes but the firewall does not have any holes drilled into it for these two booster studs...

My firewall has two studs sticking out and they are for two metal clips that hold the wire bundles...it seems that these wire clips were only on the manual brake cars?!?!?

I ordered a power booster reinforcement bracket so hopefully it will mount to four of the 8 holes.

The service manual definitely shows the top booster studs being inserted into the top two holes on the firewall and the reinforcement bracket so can do I just knock in the two top studs and mount the reinforcement bracket to the firewall???

Did Mopar use the same steering column support bracket and firewall holes for the power booster cars and the manual master cylinder cars? It just seems odd that the holes are not lining up.

Has anyone else performed this conversion and had the same issue?

THANKS for your help!!!

[anlauto]

The two studs have to be removed if you're using factory parts. YES Chrysler used two different pedal brackets for manual vs power brakes....the only difference being those two studs...