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Exact fit available in 3 sizes?

Old 12-05-2014, 01:35 PM
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Default Exact fit available in 3 sizes?

I'm looking at replacement catalytics that are labeled as "exact fit", but the inlet/ outlet sizes differ on all of them. They range in sizes from 2" up to 3". The diameter of my crossover pipe & intermediate pipe is 2.25". Do I want a Cat with 2.5" inlet/outlet so it will slip over my pipes & then weld it into place? Or should I get a Cat with 2.25" inlet/outlet & it will get welded on "nose to nose"? Thanx in advance for your input
Old 12-07-2014, 08:35 PM
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IMO the best bet is to do 2.25". If you take it to an exhaust shop to get it welded on, they'll have a hydraulic pipe expander. The best fit way would be to cut the factory cat out shorter by a few inches on each end. Then they would expand the inlet of your new cat, and the inlet for the back of the downpipe, slip everything together- and weld it back up to fit.

With 2.5", you'd definitely be having to do a good bit of filling with weld. With the pipe expander, they can get the fit fairly tight to start with so you've got minimal gap to fill with weld.
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