70 LT-1 exhaust question

[Mike E.]

Re: 70 LT-1 exhaust question

Kim--
Unfortunately the car is in my 20 degree barn, behind two other cars and not at all accessible. I don't recall anything obvious about blackout on them, but I reinstalled them in 2002, so I could easily have forgotten much by now.

[Steven C.]

Re: 70 LT-1 exhaust question

Kim,
As a fellow LT-1 owner I will tell you that having an original exhaust system is an exterme rarity. I highly recommend you use it and if not preserve/save it for future use. The center/rear pipes and mufflers are the same as big block cars but the header pipes are unique to an LT-1 car as the pipe goes from 2 inches at the manifold to 2 1/2 inches immediately after the manifold. Original pipes will not have a weld present to accomplish this. The center/rear pipes will have the "wrinkle" bends where the changes in direction take place. No clamp will exist just ahead of the muffler. The header pipes will not have the wrinkles but will have the unique change in diameter mentioned above.
With the original system you will get all the originality points and will lose a few condition points. No aftermarket system will do much better than that and most will do worse.
I agree with Terry in that you should just leave it alone as far as the rust is concerned.

Hi Dave, good seeing you in FL. Are these original header pipes?

[Dave S.]

Re: 70 LT-1 exhaust question

Hi Dave, good seeing you in FL. Are these original header pipes?

Steve,
Nice to see you as well. That is always a great time. Those are as real as can be in my opinion. You proabably knew that but they have my vote. When you get tired of looking at them let me know.

[Dave S.]

Re: 70 LT-1 exhaust question

Steve,
The original steel cities gray 72 LT-1 that was judged in Kissimmee had all original exhaust. Don't see to many like that.

[Steven C.]

Re: 70 LT-1 exhaust question

I believe my center/rear section is original as well. No clamps on it, with correct wrinkles. Not sure about the mufflers. Original CA NA9 cars are like that. Should be on the circuit later this year, perhaps Boston?

[Joe L.]

Re: 70 LT-1 exhaust question

Hi Dave, good seeing you in FL. Are these original header pipes?

Steve-----



Yes, these are GM #3913895, left side, and GM #3877210, right side. They were replaced by GM #334940 and GM #334926, respectively, in mid-1973. The latter were the forward pipes used in PRODUCTION for 1973-74 2-1/2" small block exhaust and also the ones with the "welded" rather than "swaged" reduction section to the manifold flange.