2.5” exhaust kit for 85 suburban?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

txaggie

Full Access Member
Joined
Apr 1, 2024
Posts
64
Reaction score
91
Location
austin texas
First Name
kris
Truck Year
1985
Truck Model
suburban C20
Engine Size
454
Howdy all!

Does anyone know of a 2.5” full dual kit for a suburban? All I can find is 2.25”.
 

TotalyHucked

Full Access Member
Joined
Feb 24, 2020
Posts
2,832
Reaction score
9,139
Location
Auburn, Georgia
First Name
Zach
Truck Year
1985
Truck Model
Sierra 1500
Engine Size
5.3
There are very few “kits” for these trucks. I’ve always just gone to the muffler shop and had a whole system bent up. Works out to be roughly the same cost usually and much better fitment
 
  • Like
Reactions: WFO

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,057
Reaction score
1,856
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
There are many 2 1/4” kits, so they are reasonably priced and easy to find. There is only one off the shelf 2 1/2” kit for 2WD vehicles that I’ve seen, and I think the brand was Pypes. It was at least double the price of the 2 1/4” kits, but it was also higher quality tubing.
How deep are your pockets?
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
29,217
Reaction score
24,361
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454

txaggie

Full Access Member
Joined
Apr 1, 2024
Posts
64
Reaction score
91
Location
austin texas
First Name
kris
Truck Year
1985
Truck Model
suburban C20
Engine Size
454
Without cross referencing part numbers, I can just about guarantee that's a listing error. It should be 2.25" pipes and besides that, they are crush bent and not mandrel bent.

Besides Pypes, Hooker also used to offer a 2.5" kit. Iirc, it was the "Super Competition" line. They also had a 2.25" kit that was much cheaper.
Ugh, maybe I just run with this kit anyway? I wonder how much a difference 2 1/4 over 2 1/2 will be?
 

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,057
Reaction score
1,856
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
If you have a relatively stock vintage 454, slightly smaller exhaust will not make much difference. Just make sure you get good flowing mufflers and an H or X pipe so you make the best out of 2 1/4” exhaust.

There are flow limits in the older heads, limits to stock iron intakes, low compression, and many other suboptimal features of a stock engine. A little better exhaust won’t solve those problems. Now if you already had high performance heads and intake, high compression, high performance cam, and large tube headers, then the smaller exhaust might be a limiting factor.
 

txaggie

Full Access Member
Joined
Apr 1, 2024
Posts
64
Reaction score
91
Location
austin texas
First Name
kris
Truck Year
1985
Truck Model
suburban C20
Engine Size
454
Thanks! In the next 6-12 months, heads, fuel injection, and cam will commence. I might as well put the right exhaust on for that now I’m guessing.
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
29,217
Reaction score
24,361
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
Ugh, maybe I just run with this kit anyway? I wonder how much a difference 2 1/4 over 2 1/2 will be?

Probably not that noticeable for the average fella. The crush bends definitely don't help though.
 

CalSgt

Full Access Member
Joined
Oct 3, 2021
Posts
1,540
Reaction score
3,275
Location
CA
First Name
Casey
Truck Year
1980
Truck Model
Chevy K-10 Custom Deluxe
Engine Size
350
If you’re willing to do some welding and spend the time to fit everything this Flowmaster kit is a decent option, looks like the price has gone up a little since I did mine (I did same kit but in 2.25).

The only thing it didn’t have was the mufflers, flanged connectors for manifolds, and I bought one “U” bend to cut up so I could get the fit just perfect. I could have done without the u bend if I didn’t have to sweep the pipe away from the frame mounted fuel filter.

You must be registered for see images attach


You must be registered for see images attach


Here’s the U bend cuts I was talking about.
You must be registered for see images attach
 

peats

Full Access Member
Joined
Dec 2, 2016
Posts
293
Reaction score
242
Location
Pennsylvania
First Name
john
Truck Year
72k5, 81c10 short step, 83k10 short fleet, 03 SSR. 25 chevy doodlebug
Truck Model
k5 c10 k10 SSR doodlebug
Engine Size
406 360 6.2 5.3 171
You can buy the 2 1/2" pipes pre bent for over the axle and out the side on the net. I would suggest a local muffler shop for the engine to the mufflers. Don't waste your time or money on a crossover or H pipe, they produce minimal performance gains.
 

Latest posts

Forum statistics

Threads
42,343
Posts
914,039
Members
33,846
Latest member
JOD26
Top