LIQUIDDRAGON

i got a set of 55 - 80 Corvette Ceramic Coated Ranmhorn Replacements McJacks Exclusive 1 3/4' Tubing to a 2 1/2 Collector headers for my 1976 vette. i want to run the stock undercar exhaust BUT what i didnt know is that the headers that i got dont bolt up to a stock front Y pipe. does anyone know a place that sells the front Y pipe that is 2 1/2" at the manifold?

mcjackscorvettes

hmm.. They bolted right up to my factory Exhaust. Give Jack a call, he'll take good care of you!

Billysvette

What do you guys think of mcjacks ram headers,they just dont look like they would flow that well,pipes going right into another one in the beginning.seems there would be a restriction there .

FB007

I think they will be noisier, but that's about all.

jb78L-82

I have a 78 L-82 4Spd with McJacks shorty headers, 1 5/8 to 2 in collector hooked up to 2.5 in true duals made for the orginal ram horn exhaust manifolds with the 2 in collector. I have made progressive changes to the original stock 2.5 in y exhaust over the last 25 years so I can tell you the change each modification made to the exhaust and its effect. First to go was the cat which made the idle sound better and added a little power. Next was the addition of Monza Turbo mufflers which again increased the sound at idle and driving. Next was the addition of the 2.5 in true duals which really helped with power and sound. Last, about 2 years ago was the McJacks headers which made a noticeable increase in power and sound, especially at higher RPM's. The fact that the exhaust got noticeable louder with an increase in power with McJacks headers tells me that more air is flowing through the exhaust. Having 1 5/8in headers primary tubes, short as they are, is definitely an improvement over the ram horn exhaust manifolds, though not bad, are more restrictive. The advantage of McJack headers is the preservation of low end torque at the expense of maximum power at high RPM that you would get with long tube headers. Unless your engine spends lots of time above 5,000 RPM, long tube headers on the street are a marginal advantage. McJacks headers also are a piece of automotive art. As for the original question on the thread, big block true duals as well as some of the early 70's SB true duals were made to hook up to a 2.5 in collector. I would research these dual pipes and contact the vender about just purchasing the front sections that hook up to the 2.5 in exhaust manifold. The rest of your exhaust would fit perfectly using just the two front sections. I highly recommend McJacks headers since they eliminate most of the hassles involved with block and long tube headers along with some performance improvement!

XrayOne

Check Corvette Central for exhaust. I use a CC 2" to 2.5" system. I ordered a McJacks 2" collector Rams Horn replacement. They bolted right in. Also I ordered the installation parts from Jack. The doughnut has a larger hole in it with a short steel pipe inside. The original had an adapter that was smaller on one end and extended on both ends. The new one is larger than both and nestles in both flanges. I do not hear any more noise, they look awesome. Still freezing here so I don't know about power but everything is freed up from stock. Update. I know it's a response to an old question but I have found so much helpfull "old info" on this site it may help the next guy. Cheers.

speedreed8

hopefully he figured it out 6 years ago,

LIQUIDDRAGON

Yeah I did figure this out almost 6 years ago. I took it in to a custom exhaust shop and they took care of me. Ended up paring that car out while I was stationed in California because it was getting to expensive to ship around the country with me every three to four years.

Billysvette

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