Fordnatics List Archive

This read-only message was archived from a public mail list.
Mail From: "Bob Hickman" <(email redacted)>

Subject: Exhaust Questions
I'm planning on replacing the exhaust system on my 1968 F250 4x4 and have some
questions. The motor is a 460 with an Edelbrock Performer 460 manifold,
Edelbrock Performer 750 carb, and Comp. Cams 268H cam.

The present exhaust system is comprised of two separate pipes coming back from
the stock exhaust manifolds to a muffler on each side. The tail pipes are just
a bent piece of pipe that comes out in front of the rear wheels. All of the
pipe is 2 1/4" in. diameter.

Here's my questions:

1) Is there an optimum length for an exhaust system? Most stock systems have
the tail pipes exiting behind the rear wheels. Could my present system be too
short?

2) Should I look at replacing the present No-Name brand mufflers with something
like a FlowMaster?

3) Based on the size of the engine and the modifications made to it should I
look at a different diameter exhaust pipe?

Thanks in advance,

Bob "I got tools for Christmas and it's time to play" Hickman

This read-only message was archived from a public mail list.
Mail From: "Fontana Peter" <(email redacted)>

> 1) {too short?}
Doubtful. Are you experiencing a torque shortage?

> 2) Should I look at replacing the present No-Name brand mufflers with
something
> like a FlowMaster?
Maybe not Flowmaster, but you probably will want to replace them with one of
the "better" names. Apparently some of the cheaper (and some not so cheap)
mufflers may have in/outlets of a certain size (2.25", 2.5", etc) on the
outside of the case, but are actually quite smaller in the case - less than
2".

> 3) Based on the size of the engine and the modifications made to it should
I
> look at a different diameter exhaust pipe?

I would have picked 2.5" myself, but if you stick with the layout you have
now, 2.25" (ID) may be adequate. Do you frequent the 5000rpm+ range?