Topic: 70 Dual exhaust

[70Mach]

For dual exhaust cars: Did the 70's have the reinforcement in the rear seat area?  And did 70's use the bracket with studs or did they use self tapping bolts?  Thanks,

[70Mach]

Pictures of a 70 351C 4V dual exhaust hangers mounted to car? Thanks!

[J_Speegle]

Pictures of a 70 351C 4V dual exhaust hangers mounted to car? Thanks!

Should mount the same way as a Boss or 428 CJ car (all dual exhaust 70 cars)


Hangers and mounting/attachment points





Close up of the mounting hardware





Mounting holes left side - hardware in place right side




Hope this helps

[70Mach]

Thanks! So are the fasteners self tapping bolts or screws or was there a nut on the back side?  My car was torn apart and the holes that were in the floor looked like they were punched through and didn't have anything on the inside.  So that's why I'm trying to figure out what it supposed to be like. 

[J_Speegle]

Thanks! So are the fasteners self tapping bolts or screws or was there a nut on the back side?  My car was torn apart and the holes that were in the floor looked like they were punched through and didn't have anything on the inside.  So that's why I'm trying to figure out what it supposed to be like.

Never owned or built a 70 with dual exhaust (well not enough to tear it all the way down Believe though that the mounting bolts thread into a reinforcement plate on the top - not screws

[jwc66k]

Thanks! So are the fasteners self tapping bolts or screws or was there a nut on the back side?  My car was torn apart and the holes that were in the floor looked like they were punched through and didn't have anything on the inside.  So that's why I'm trying to figure out what it supposed to be like.

According to the 1970 Mustang Chassis Manual, you really need to invest in a set, the bolt is 381877-S2 (5/16-18X3/4 hex, washer, forming, lead point) which is a commonly used bolt for exhaust, brake and fuel line retention from 1968 into 1973, no nut required. Looking at the 1970 Weld and Sealant, I could not find a reinforcing plate, aka doubler, on the drawings. That may mean that it was pre-assembled by the supplier and not an assembly line step.
Jim