Will a Monte Carlo cat back system fit an EC?

[joe_padavano]

i thought the only difference between the frames between them was behind the rear axle, the same with the wagons.... i THINK

The 2dr, 4dr, and wagon G-bodies use a 108" wheelbase. The Caminos used a 119" wheelbase (I measured mine to be sure). Wikipedia has this wrong. Imagine that.

In addition, the rear body mounts for the wagon frames are different from the 2dr/4dr frames. This is shown pretty clearly in the Chassis Service Manual.

 

[Longtimer]

Thanks Joe. Good thing I ordered the Pypes then. They did have a unique call out for El Camino. Pypes cost more but that other sysem was "Aluminized" and dropped to 2 1/8" behind the mufflers AND was wrinkle bent. $365 gets all 2.5" Stainless and look at these bends:

They say it's a 30+ HP add over my stock single 2" system

 

[megaladon6]

and they bolt in very easily, i have the header back duals from pypes in my car. you might need to get longer header extensions. the pypes ones are pricey but damn do they look nice! (i have short collectors on my headers, so you might be fine)

 

[joe_padavano]

Thanks Joe. Good thing I ordered the Pypes then. They did have a unique call out for El Camino. Pypes cost more but that other sysem was "Aluminized" and dropped to 2 1/8" behind the mufflers AND was wrinkle bent. $365 gets all 2.5" Stainless and look at these bends:

They say it's a 30+ HP add over my stock single 2" system

Excellent choice. I've used Pypes products on some of my cars and the do a very nice job.

 

[daveSS1987]

A couple of years ago I parted out a 86 Monte SS that had flowmasters on it, used the SS converter and stock Y pipe and stock tailpipes, the 87 frame even has the rear exhaust hanger holes already drilled in the frame, BUT to answer everyones questions I had to have about 4" long pipes welded between the mufflers and the Y pipe, since the El Camino wheelbase is definately longer than the Monte SS one. But a local shop installed them with the extensions and welded everything up nice for around $100, not bad for the labor involved I guess.
Dave

 

[Longtimer]

Good info Dave, nice to confirm. Have the Pypes in the garage. Been too busy to mount. Used Flitz, a polisher pad and drill motor to polish the stainless mufflers. They turned out nice.

I have an exta old cat. I'm thinking of ordering a good low restriction cat and putting that extra 4" between the mounting plates for the cat (4 bolt flat plates at each end of the cat mount to Edelbrock Y pipe / Headers and to the pypes out back). I don't think it would restrict flow too much(?). Welding would be cheaper for sure.

 

[daveSS1987]

Good idea, but I'm not exactly sure if the extension was exactly 4", will have to measure the welded in section this weekend. Also the legnth of the mufflers may be different on each system and that will affect how long of a pipe you need. So you gonna hollow out an old cat and weld it to the new one? won't be able to get bolts in there I don't think to hold the 4 bolt plate to the converter. I would make sure to hollow out the old converter and weld a cap over the tube from the air pump so you don't get any exhaust leaks.
Keep us updated on how it works.
dave

 

[Longtimer]

I would greatly appreciate that Dave. I just measured the Pypes mufflers. The muffs themselves are 14" - add about 1" on each end as the mounting point, calling it 16" in length.

Wish I could do as you suggest with the cat. Unfortunately, the California testing includes a sniffer up the tail pipe. The only thing I can do is use a high flow cat to replace the old clogged up cat and hope it provides readings good enough to pass.

 

[daveSS1987]

I was thinking if you just weld the old hollow cat to the new one you will get an increase in legnth without needing the 2 extension pipes. But would probably be more work in the long run since you would need to cut the old converter shorter and weld it to the new converter...just an idea, not sure if it would work or not.
Dave

 

[Longtimer]

I'll have to get the new cat and the old cat next to each other and take some measurements before "surgery."