How to cram the most exhaust in there

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.

SmashBack

Full Access Member
Joined
Jun 4, 2013
Posts
57
Reaction score
11
Location
Texas
First Name
Chris
Truck Year
1979
Truck Model
Big 10
Engine Size
6.0
So I've dropped the lq4/4l80e in my 79 Big 10 (longbed of course). Had a 5" aluminum driveshaft built. I've got drop hangers and shackles out back so about 4" drop and have CPP drop spindles with stock springs in front.

About to build the exhaust with 2.5 inch piping. I was thinking I was going to run this x-pipe but I'm not sure now. Pretty certain it won't fit under the driveshaft since it's so fat, at least not without hanging down real low. I might be able to fit it above the driveshaft, but it will need to be behind the cab. Trying to make sure I've got enough room without the driveshaft bumping it. I've jacked the rear up to get an idea on how far down the shaft will drop, and have tried to measure as close as possible how far it's going to swing up as well.

Anybody else done anything similar? If I can't fit it or if it will lose its benefit because of funky placement I'll go with an H instead if I need to. Here's some pics of me playing around to see what we can do.

You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
 

4WDKC

Full Access Member
Joined
Jan 27, 2016
Posts
2,366
Reaction score
1,090
Location
Southern Florida
First Name
Kacy
Truck Year
1987
Truck Model
V10
Engine Size
350
why not route it over to the other side and make it duals that exit on one side?
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
30,446
Reaction score
28,352
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
The benefits of an X-pipe are marginal at best, hardly worth the trouble, especially when packaging is an issue.

I'd go without the X and do basic duals, with an H-pipe but only if it's convenient.
 

SmashBack

Full Access Member
Joined
Jun 4, 2013
Posts
57
Reaction score
11
Location
Texas
First Name
Chris
Truck Year
1979
Truck Model
Big 10
Engine Size
6.0
Routing both to one side is the same amount of effort IMO and I don't care for the two tips on one side. Must be some kind of OCD!

I've seen wildly varying results from X-pipes but all the results I've seen are more than marginal at best. It would be great to compare side by side on my own vehicle but I'm not going through that trouble :) I've got it sorted out now with new headers, the only thing that may give me an issue is the e-brake but I'll deal with it when the time comes.

You must be registered for see images attach
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
30,446
Reaction score
28,352
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
All the tests I've read about have shown maybe 5hp or so, and in a specific rpm range.
 

dvdswan

Full Access Member
Joined
Mar 11, 2014
Posts
2,366
Reaction score
2,036
Location
Port Orchard, WA
First Name
Dave
Truck Year
1978
Truck Model
K10
Engine Size
350
I ran 2-1/2" pipes to a y-pipe with 3" out and 3" muffler on my toy. I know its not dual but its an option.

You must be registered for see images attach


You must be registered for see images attach
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
30,446
Reaction score
28,352
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
Routing both to one side is the same amount of effort IMO and I don't care for the two tips on one side. Must be some kind of OCD!

I've seen wildly varying results from X-pipes but all the results I've seen are more than marginal at best. It would be great to compare side by side on my own vehicle but I'm not going through that trouble :) I've got it sorted out now with new headers, the only thing that may give me an issue is the e-brake but I'll deal with it when the time comes.

You must be registered for see images attach

So those are different headers than the first post? It looks like you do have it sorted well.
 

SmashBack

Full Access Member
Joined
Jun 4, 2013
Posts
57
Reaction score
11
Location
Texas
First Name
Chris
Truck Year
1979
Truck Model
Big 10
Engine Size
6.0
Wow looks like 4x4 you have to be even more creative. Who'd think on a big ole truck that the exhaust routing would be so difficult!
You must be registered for see images attach
You must be registered for see images attach


Yes, those are the Speed Engineering headers. I can't imagine using them with any mounts other than the Tejas with how low they'd hang (a lot like the Summit brand I had on the 350, so terrible). I was this far in so spending an extra couple hundred bucks to get optimal fitment was worth it for me.

If the engine were any lower I'd recommend the Schoenfeld headers for sure.

Working on the pipes rearward of the x-pipe now, trying to decide what to do there. Looks like running all the way back and hanging the mufflers (center in, offset out) I may be able to run a straight pipe from the offset out over the axle and then a 45 or two to get them pointed out behind the rear tires. That's assuming coming off the muffler will put the pipes above the bottom edge of the frame rail. I like to tuck them up and just have a little tip showing.
 

shiftpro

Full Access Member
Joined
Aug 31, 2012
Posts
4,855
Reaction score
6,092
Location
BC Canada
First Name
shiftpro
Truck Year
73-87
Truck Model
1500, 2500, 3500
Engine Size
350, 383, 454, 496!
So I've dropped the lq4/4l80e in my 79 Big 10 (longbed of course). Had a 5" aluminum driveshaft built. I've got drop hangers and shackles out back so about 4" drop and have CPP drop spindles with stock springs in front.

About to build the exhaust with 2.5 inch piping. I was thinking I was going to run this x-pipe but I'm not sure now. Pretty certain it won't fit under the driveshaft since it's so fat, at least not without hanging down real low. I might be able to fit it above the driveshaft, but it will need to be behind the cab. Trying to make sure I've got enough room without the driveshaft bumping it. I've jacked the rear up to get an idea on how far down the shaft will drop, and have tried to measure as close as possible how far it's going to swing up as well.

Anybody else done anything similar? If I can't fit it or if it will lose its benefit because of funky placement I'll go with an H instead if I need to. Here's some pics of me playing around to see what we can do.

You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach

hey Chris can you please further explain how you dropped your engine and tranny? I take you dropped it a bit lower in the frame? I'm confused because you also mentioned dropping the suspension... How is your oil pan not sitting on the road? I'm trying to picture this and only seeing a train wreck, please advise... it sounds interesting!

Also, in your photo (side view) it look like the tail of the transmission is pointed lower than the angle of the driveshaft? is that what I see? Because if it is, I'm afraid that might be problematic for you down the road... like literally.
Maybe the pics are just in mock up stage... most likely..
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
10,041
Reaction score
10,134
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
X pipe, H pipe, make it easy on yourself, there's no difference!
ESPECIALLY not for a street truck...:rolleyes:
 

SmashBack

Full Access Member
Joined
Jun 4, 2013
Posts
57
Reaction score
11
Location
Texas
First Name
Chris
Truck Year
1979
Truck Model
Big 10
Engine Size
6.0
hey Chris can you please further explain how you dropped your engine and tranny? I take you dropped it a bit lower in the frame? I'm confused because you also mentioned dropping the suspension... How is your oil pan not sitting on the road? I'm trying to picture this and only seeing a train wreck, please advise... it sounds interesting!

Also, in your photo (side view) it look like the tail of the transmission is pointed lower than the angle of the driveshaft? is that what I see? Because if it is, I'm afraid that might be problematic for you down the road... like literally.
Maybe the pics are just in mock up stage... most likely..

Maybe that was a little ambiguous. By dropped in a meant I installed it. The Tejas mounts raise the engine and trans vs other mounts.

The only picture showing the trans/shaft angle is before it was shimmed up so yes it was bad in that picture.
 

shiftpro

Full Access Member
Joined
Aug 31, 2012
Posts
4,855
Reaction score
6,092
Location
BC Canada
First Name
shiftpro
Truck Year
73-87
Truck Model
1500, 2500, 3500
Engine Size
350, 383, 454, 496!
Maybe that was a little ambiguous. By dropped in a meant I installed it. The Tejas mounts raise the engine and trans vs other mounts.

The only picture showing the trans/shaft angle is before it was shimmed up so yes it was bad in that picture.
Oh that makes more sense, sorry I was having a blond moment too.
Well post more pics as thing progress. Curious to see if you can get that x-over in there.
 

Blue Ox

Turning Diesel Fuel Into Fun
Joined
Mar 27, 2018
Posts
5,221
Reaction score
12,025
Location
LI-NY
First Name
Derek
Truck Year
MCMLXXXV
Truck Model
K20HD
Engine Size
6.2L
If you make the X or H cross under the driveshaft it can double as a D/S hoop.
 

Latest posts

Forum statistics

Threads
44,173
Posts
950,865
Members
36,288
Latest member
brentjo
Top