cshaw07

iTrader: (14)

well a couple.. does an rb header replace the pre cats on an 82 12a car?

and if i remove the main cat on the same car, cut the flanges off and weld a piece of straight pipe in there, would it be the same as a "race pipe"? I have a spare stock exhaust that i would use the thick walled piping out of to weld in. Im not really being cheap, but if i can make the same thing, or close to, then why not?

mazdaverx713b

iTrader: (91)

the header will replace the pre cats and instead of cutting the flange off of the converter, you can buy a new flange from mazdatrix or racing beat and weld in a "test" pipe in place of the converter.

bmeyer

iTrader: (5)

make sure the measurements are accurate, i learned that the hard way. i ended up having to butt weld on 3 more inches. just get two flanges and put a pipe or presilencer in there. it is also loud and annoying with a header straight to a stock muffler.

LizardFC

iTrader: (1)

I had mine done in a muffler shop with the car up on the lift so we could test fit everything. The guy was nice enough to let me help. I don't know if the 85 setup differs, but my header ends roughly where the main cat would begin. And like BMeyer said, straight header to muffler is quite loud and pingy... I would recommend a presilencer.