LT1 Exhaust Manifolds

Canadian Poncho · A Poncho Legend!

LT1 Exhaust Manifolds

4SPEED427 · A Poncho Legend!

There's a very good chance it has manifold bolts that are broken off in the head as well. A common flaw on the LT1.

LT1Caddy · Poncho Master!

A very common problem, most are NOT cracked. I had a 94 Fleetwood with an LT1 in it. Awesome car, fast, sleeper and it got super mileage on the hwy...25+ easy. (I got a lot better on just hwy, not mixed.)
Back to the story, I had both of mine fixed, at different times. The end manifold bolts were the real culprit. GM used a stud with a nut welded on it, not a bolt. The steel was so cheap that the stud would deteriorate being 2/3 its original size when removed. Some of them, the nut part would break off, hopefully leaving enough of the stud to be able to remove it. Some broke in the head and had to have a bolt welded on them to remove.
But when the manifold was removed it would have to be taken to shop with a belt sander and the surface brought back to square. This was because the end stud would break, then with high heat from driving, it would finally drop the gasket between the first and second stud, then you would start to hear the exhaust leak. By that time in very few miles the torque from the overheated manifold would break the next stud. This would happen within a few hundred miles...

I would check on line with Car-part.com or your closest wrecking yard. Buick, Impala ss, Caddy Fleetwood 94-96 all the same car.... Impalass website

Canadian Poncho · A Poncho Legend!

Thanks for the info Bruce. I passed this along to my friend. This is the car in question. 210k on it. "Rust Free" apparently. Those wheels would need to go in my opinion

LT1Caddy · Poncho Master!

94-96 Impala SS wheels would like good... There was a "mag" wheel option for the Caddy too. google it..

73SC · A Poncho Legend!

I wouldn't have a problem using headers on that engine, with OEM style mufflers it would be fine.

I really don't like messing around with Cadillacs, the OG wheels look great on that car and mine never had a vinyl top which was rare but looked so much better.

Can only find a photo that Hillar took at the dealer when I bought the car.

CityCadillacShow08 007.jpg

LT1Caddy · Poncho Master!

Ray.. Do you still have that car ?

4SPEED427 · A Poncho Legend!

LT1Caddy wrote:

A very common problem, most are NOT cracked
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You and I will have to disagree on that. While I never had either a cracked manifold or broken manifold bolt in over 300,000 kms of LT1 ownership (1 Roadmaster, 1 Fleetwood, 2 Impala SS's and 1 Trans Am), I spent many years frequenting the Impala SS forum. Cracked manifolds were very common among owners on there but most of those guys drive their LT1's a lot harder than I do and that makes more heat.
Also, working at the GM dealership I saw a few LT1 B body police cars with cracked manifolds which totally makes sense because they see lots of hard use.

LT1Caddy · Poncho Master!

It was back in 1999-2001 so maybe it wasn't as prevalent then. My car was a special order out of Dallas Texas. I bought it from an older guy from Nova Scotia that used it to commute to Florida.
It had some "odd" options on it that were used on fleet cars. I used my contacts at GM to get the option sheet on it, no SPID sheet on the trunk. We came to the conclusion that it may have been ordered for Government use.
Silver grey, deleted vinyl roof, HD seat frames (?)....
I drove in from Toronto to the 50th Corvette anniversary at Bowling Green, got 30+ miles to the gallon. Great car

4SPEED427 · A Poncho Legend!

We had a 94 Fleetwood for about 5 years. I bought it specifically to haul our tall son and his tall friends around to basketball games through high school. His friends loved the car because they finally had enough legroom! What a great car. Such a nice ride, so good on fuel. I hated the stupid traction control though but that was an easy accidental fix. I must have damaged one of the wheel speed sensors one day when I changed a wheel bearing because after that we had a solid ABS light and the traction control never worked again. Suited me just fine...

LT1Caddy · Poncho Master!

There was a shut off for the traction control in the glove box......Yup

4SPEED427 · A Poncho Legend!

I know but you had to do it every flippin' time you started the car and those cars are so wide, it was a long way to lean over and open the glove box every time.

LT1Caddy · Poncho Master!

4SPEED427 wrote:
I know but you had to do it every flippin' time you started the car and those cars are so wide, it was a long way to lean over and open the glove box every time.

Yeah you are right, I'm 6'4"

4SPEED427 · A Poncho Legend!

I sometimes debated removing that switch and mounting it somewhere on the driver's side of the car where it could be reached sitting normally in the seat. I'm 6'1" and I couldn't do it if I had already buckled up before remembering it.