304 CJ5 exhaust system

Guys,

Looking for recommendations for a muffler for a 1973 CJ5 with 304. Want a short Flowmaster 44 series or something similar. Do you recommend a central input pipe with offset output? What works? What diameter pipes? I'd think 2.5" would be plenty for a small displacement truck V8. Do you agree?

Thanks,
Chilly

 

My research on this board and others seem to be that 2.5" single pipe all the way through is good, Flowmaster is a good choice in the 40 or 50 series. Can't answer the offset question.

It also seems that exhaust is a personal thing...kind of like what seats you want to put in the Jeep. They all work...but which one do you like best?

 

I know for me I have the dual exhaust and the pipe size is 2", I go through some glass packs at the moment, plan to change to cherry bombs cause they are short and small and run them through some tail pipes and exit each side behind the rear tires.

Good luck

 

Good topic since I am just in the middle of this same discussion with the exhaust shop. Scott at Extreme Gear Offroad told me that the 40 series sounds good, but during longer drives the resonance would drive him crazy. He recommends the magnaflow with 2.5 to the muffler and 2.25 to the tail pipe for better mid-range.

 

Didn't think to specify, but I'm going with 2 into 1, then into muffler, then exit behind the left rear tire. I appreciate a little rumble but not looking to make a statement. And I do tend to think a conservative pipe size is plenty for a torque-minded, low revving small displacement engine.

 

I'd say a 2-1 is the way to go, I have duals on my stock 74 304 renegade with edelbrock shorties, 2.5" pipes, glasspacks (can't wait to ditch them for magnaflows!) and exits at each back corner. I feel I have too much cyl scavenging, and an X or H pipe far up enough is a difficult notion on a cj5.

the shorties are a very good header choice in my opinion as an alternative to conditioning stock manifolds, but the stockish pipe setup beyond that is well matched to a stock 304. too bad they only sell the 1976 up front pipes. one may fit with the correct heat riser on the pass side manifold. I did dual 'J' tubes from the shorties.

 

When I did my V-8 swap I went with 2.25 inch tubes and used Thrush Chambered Mufflers (Magnaflow clones). I used the offset-offset configuration which let me angle the mufflers up closer to the body under the seat area (inlet low/outlet high) to get better ground clearance.

 

Well, today I was at Advance Auto and they actually had a Flowmaster Super 44 series with 2-1/2" inlet and outlet, both offset. I took it home and it seems like it will lay up nicely if the exhaust shop does their part. Intend to have the inlet tucked near the frame then offset the outlet toward centerline so it will clear the parking brake cables, then whoop-de-doo back outboard between the gas tank and tire, dumping out behind the tire.