1973 K20 Muffler Size

[TheWhiteElephant]

I have decided on a pair of Dynomax Super Turbos for my 1973 K20. I am running 2.5 inch ram's horns. I've gotten a couple of estimates from 2 muffler shops for $340 for the mufflers, aluminized pipe, gaskets, and hangers, that will have turn downs ahead of the rear axle.

I'm trying to see if it would be less expensive for me to purchase the mufflers from Summit and then have the shop do the rest. Anyone know what the OEM size for the mufflers on these trucks is? Also, I'm assuming I have to get the 2.5 inch inlet/outlet, correct?

Any thoughts would be appreciated.

[donut]

To me it seems like you should coordinate with whatever shop is doing the work, with what they rake off for you supplying the mufflers may be less than what you'd pay Summit. Some places are funny like that.

I believe my K-20 was a single 2" in and out, but the original exhaust may have been rotted out by 1975.

[gchemist]

A 14" muffler will be fine. I bought a converter from Summit. I had a shop install it. Saved $65 from the total cost if I had bought and installed from the shop.

[TheApocalyptican]

It just depends on how much the shop actually charges for their mufflers. I bought my flowmaster off of summit, and had a shop install it. Found out while I was there that they charge the same amount I paid thru summit.