stock exhaust diameter?

[aramil]

what is it i know its 2" or bigger but im not for sure. i know someone on here knows and it would really be helpfull when i start planning my exhaust set up.

[Dragon]

My manifolds (cast Iron) are 2-1/4

[sideoilerfe]

Your stock exhaust system on a 360 was 2 1/4" off the manifolds into a single 2 1/2" pipe. The muffler had a 2 1/2" inlet with a 2" outlet so your tailpipe was only 2".

[aramil]

thanks, i needed to know the muffler size so this helped a lot since i dont know how to measure pipe diameter with a tape measure. why did they restrict it down to two inches after the muffler?

[sideoilerfe]

I don't know why they restricted it like that. Possibly more low end torque but mine had problems going above 70 MPH until I replaced the muffler and tailpipe with a 2.5". I would suggest going that route.

[Dragon]

They made it smaller in stock form to clear the spare tire.

[sideoilerfe]

They made it smaller in stock form to clear the spare tire.

That's funny, My 2.5" clears it just fine on the '68. And on my '70, my 3' clears it as well. So, that cannot be true.

[aramil]

does the smaller tail pipe diameter help with low end torque by restricting the flow though? i learned another wierd fact about our trucks thanks

[Dragon]

They made it smaller in stock form to clear the spare tire.

That's funny, My 2.5" clears it just fine on the '68. And on my '70, my 3' clears it as well. So, that cannot be true.

You still got your original stock pipes after all these years? We used to have to move the mounting points on the early trucks at Ford because people complained. The pipe came over the rear end and then turned right in front of the spare tire and would leave rub marks in the spare due to shifting.

[sideoilerfe]

I did on the 68 until I cut it off to replace it with a 2.5". A simple remedy is if it rubs the spare tire is just to slide the tire over a bit. Besides, your explanation of the tailpipe only being 2" to clear the spare tire doesn't explain why the trucks that had the "short" tail pipe which exited in front of the rear wheel still had the same 2.5" inlet and 2" outlet muffler with a shorter tail pipe.

Besides, my '70 has a 3" now and doesn't rub at all.

[Dragon]

It is just the difference in how Ford originally bent it on an auto bender and shops bend it now by hand on mandrel benders to make them fit,

My work trucks with full bed get it behind the rear wheels. My flat bed dumps behind the carrier bearing straight down and my Hot rod trucks always before the rear wheels

[sideoilerfe]

My flat bed dumps behind the carrier bearing straight down :

I've wondered why large trucks do this? There's room for a longer tailpipe yet they still keep it short. I personally don't want to listen to it so I have my pipe as long as possible.

[Dragon]

Maintenance costs on the older ones but by law you only have to get the exhaust past the passenger cabin. I was looking at a new LCF to put my Boom Bucket and utility on. The Diesel pipe dropped out right behind the tranny and overdrive.

If you dump the exhaust under a stock bed it flows everywhere when not driving forward.

[sideoilerfe]

If you dump the exhaust under a stock bed it flows everywhere when not driving forward.

But not on a flat bed?

[Dragon]

pic102406_12.jpg

This is why they dumped so soon. 10 foot bed with factory rear frame extension.

Yes because you don't have the sides to trap the exhaust like a bed. Here a company that takes bedless factory trucks build an extension to the exhaust because all their beds have lowered sides for tool boxes or fuel tanks.