70 LT-1 replacement mufflers

[Patrick B.]

My original mufflers lasted well into the 80's until I replaced them with sidepipe headers. Big mistake. Later I put on stainless pipes and Dynomax mufflers. However, the car is still much louder than with the original equipment mufflers and it also lost a couple of MPH in the 1/4 mile.

I understand the original mufflers were made by Walker (as are the Dynomax). Is there a replacement that duplicates the sound and performance of the originals? Judging appearance is not a concern. Were the LT-1 mufflers different or the same as all other 2.5 inch mufflers?

[Bill C.]

Re: 70 LT-1 replacement mufflers

only mufflers that sound the same as original ones are NOS.....

I have not found any even close - they are all to quiet.

]3943386 and 3943385 are the GM part numbers.....Maybe someone has a better line on repro mufflers ....

[Joe L.]

Re: 70 LT-1 replacement mufflers

My original mufflers lasted well into the 80's until I replaced them with sidepipe headers. Big mistake. Later I put on stainless pipes and Dynomax mufflers. However, the car is still much louder than with the original equipment mufflers and it also lost a couple of MPH in the 1/4 mile.

I understand the original mufflers were made by Walker (as are the Dynomax). Is there a replacement that duplicates the sound and performance of the originals? Judging appearance is not a concern. Were the LT-1 mufflers different or the same as all other 2.5 inch mufflers?

Patrick------


The LT-1 mufflers were the same as non-LT-1 2-1/2" mufflers.

I know of no muffler that duplicates the sound of the GM mufflers. At least, none that are currently available.

However, I do not know how close the CURRENT offerings of Corvette Central, Gardner, and Allens might be.

A muffler is like a musical instrument. Every facet of its construction affects the sound. In order for a reproduction muffler to sound like original mufflers, it would have to duplicate the construction of the original muffler in EVERY way.

By the way, I totally agree with your assessment that going to the headers and side pipes was a big mistake. I would NEVER, EVER install either headers or sidepipes on a Corvette. If I were to purchase a Corvette that had either installed, I'd remove them so fast it would make your head spin.

[Peter M.]

Re: 70 LT-1 replacement mufflers

Joe - why so anti header?

Bill C - nice Challenger! Sharp colors too

[Patrick B.]

Re: 70 LT-1 replacement mufflers

Bill: The Dynomax mufflers are certainly not too quiet, but the noise penalty does not seem to yield any performance benefit. The original mufflers actually made more power with the detuned ZL-1 that has been in the car for 29 of the 39 years I have owned this car. I am slowly replacing the go fast stuff I put on the car over the years with the original parts, but I think I'll keep the motor for a while longer but put on an LS-6 manifold so I can replace the LT-1 hood.

[Joe L.]

Re: 70 LT-1 replacement mufflers

Joe - why so anti header?

Bill C - nice Challenger! Sharp colors too

Peter-----


Too much extra heat which finds its way into the passenger compartment and too much maintenance. Plus, way too non-stock appearance.

Do they make extra power? Of course they do in most cases. However, it's extra power that's totally unusable in a street situation if one drives even close to within rational, if not legal, limits.

[Terry M.]

Re: 70 LT-1 replacement mufflers

Peter-----


Too much extra heat which finds its way into the passenger compartment and too much maintenance. Plus, way too non-stock appearance.

Do they make extra power? Of course they do in most cases. However, it's extra power that's totally unusable in a street situation if one drives even close to within rational, if not legal, limits.

Hey Joe is that why some people put a ZL1 into their 1969? Do you have that running yet? You could drive it to the National in San Diego next year -- hint hint.

[Patrick B.]

Re: 70 LT-1 replacement mufflers

A ZL-1 is a natural swap for an LT-1 car. It is happy with the LT-1 radiator, shroud ,fan and springs. The side pipe headers did not put heat into the passenger compartment, but put lots of heat directly on your leg if you weren't careful entering and exiting. The noise and looks were the drawbacks.

I inquired to Walker about mufflers since their online listings only go back to 1979, but they just responded that they had nothing for a 70 LT-1.

[Michael M.]

Re: 70 LT-1 replacement mufflers

Patrick, I have a pair of mufflers part #3943386, #3943385. The part numbers are embossed along with W - 11 - 85. I think the W would stand for Walker and 11 - 85 is the date the muffler was made.

[Patrick H.]

Re: 70 LT-1 replacement mufflers

Hey Joe is that why some people put a ZL1 into their 1969? Do you have that running yet? You could drive it to the National in San Diego next year -- hint hint.

And San Jose in his backyard a couple of years ago, but...

[Joe L.]

Re: 70 LT-1 replacement mufflers

Hey Joe is that why some people put a ZL1 into their 1969? Do you have that running yet? You could drive it to the National in San Diego next year -- hint hint.

Terry------


I could have built the "ZL-1" to far greater horsepower than I did. However, I kept it to about 475-500. Even that's about 200 HP in excess of anything I could possibly use on the street and I can virtually guarantee you that those extra 200 HP will never be used. They're just "there".

It's not quite done yet but it's ever so close. I spent the day before yesterday working all day on rebuilding the front suspension and brakes on the old '89 Eldorado I hardly ever drive. What a pain working on that car.