Somebody had changed them out,,,,,same dilemna with bolts as Tori is having.....my tubes had the **** beat out of them for clearancing everrywhere. I've had 5 Mopar class c's(Dodge/Fireball right now w/360) All except the one BB were 360 w/ stock manifolds. I'll stay with the OEM manifolds any day of week, never had the OEM's crack. All had 4:10 rear gears....PLENTY of pulling power....3+ grand @ 55 mph really sucks though & forget any decent gas mileage(never better than 7 mpg regardless where my foot was at w/ throttle,,,,freeway or town, it didn't matter) I'm either changing the rear gear on the Fireball or try to find a remote overdrive unit. My 74 Dodge/Tioga did hole shot a Lexus IS 300 consistently though.
