Hello:

I was wondering if it's possible to just swap the stock muffler with a 40 series Flowmaster on the '99-2000 F-150s with the 5.4 engine. Would the stock one be larger than the Flowmaster? What diameter is the pipe on the stock muffler/pipe? 2in.?

Thanks for your help.

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'79 F-150 Ranger,Lariat, C6,auto,460,429 heads,2:73 gears, candy apple red, Flowmaster 2-chamber 40 Series,2.5" duals,SenDel mags,lund roll pan, spray-in boxliner. Kicker 10" Impulse Subs/Clarion 7575 Deck, Clarion 6 1/2" Door Speakers

 

Mad dog,
I have a 2000 4.2l and I got the 40 series flowmaster no problem. On my particular model the flowmaster is significantly smaller than the stock muffler. If I were you I would call around the local muffler shops and ask them what would be best for you.

Just my $.02

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2000 150 sport solid white, K&N filterpack the rest is still stock....for now anyway!

 

I cut the muffler off my 99 Lightning today and left the cats. I love it.



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Red 99 Lightning #812 4/30/99 (Totaled)
Black 99 Lightning #1542
5/25/99
White 88 SVO Merkur Xr4ti
Sand Gold 88 Xr4ti
Silver 95 SHO
Red 99 Prelude SH adopted