Interesting development.

[Thumpin455]

Sometime in the last two years I ordered a full exhaust system from Summit, the cheaper ones without the mufflers bust still mandrel bent. I remember ordering 2.5" pipe for the 65 GTO and when it got here I never opened the box, it just went out to the shop and stayed there. Well yesterday I helped one of the local guys with his Maverick, and he wants to keep his sidepipes, so I was looking for header flanged reducers. I opened this box to see what it had in it, and found it was a 3" system for the 64-72 A body. Im pretty sure I ordered 2.5, but hey with my memory who knows. Regardless, the 3" is too big for the 65, it just isnt going to need that much pipe, so it will go on the 70.

Or maybe I ordered it for the 70 and it was 3" all along.... Either way, even if Summit screwed up it is a bonus for me, if I just remember wrong, well its still a bonus since I need it for the 70. They arent terribly expensive so I can get a 2.5" system for the 65 easy enough, and I am a step ahead of where I thought I was.

Its probably my memory, I have found 455s and 400s sitting at my dads that I have no idea where they came from or how they got there. I have to sit down and write a list to remember what cars I have, so this would be a bit harder to remember.

[oldsman71]

thats pretty big exhaust!

[Huskinhano]

Todd, sounds like you're getting to that age with CRS like the rest of us old farts. I don't know how many times I've said I'm going to make a list but forget to. Maybe I should start a list to start a list.

Seriously, can you go too large on an exhaust system? With headers, IMO, yes but the rest of the system, I'm not so sure other then you can go too small. We can beat Charles and Boyles gas laws to death but it's most likely describing the conditions of the gas flow rather then power losses. Heck, they put 3" aftermarket systems on 5.0 Mustangs and no one says they're costing power.

[Thumpin455]

Well the 70 needs it, the 65 doesnt, since its getting a mild engine. I dont need stuff banging around and thumping the floorboards on the 65 since I wont be driving it. I can put up with that, I doubt Dave would.

[Schtauffer]

FWIW, I used to have 3" duals on the Monte. I took those pipes off and have dual 3" Y'd into a single 3.5" tail pipe, and the car picked up a tenth and a half.

[Stich496]

3" duals are to big..

[squirrel]

too big? I guess that depends on how thumpin your 455 is

[Thumpin455]

too big? I guess that depends on how thumpin your 455 is

The one in the 70 will be just fine with the 3" its 455 is pretty thumpin, the 65 will be too loud with them, one is a hotrod, the other is a cruizer. They will both rumble, and the 65 is getting the old 455 from the 70, so the idle will sound quite nice with the right mufflers. The right mufflers being Summit $20 turbo mufflers.... cheap and really nice sound to them behind that 455.

[TC]

3" to big??, That's all I'd ever run...... I don't believe in back pressure.......

On my friends Chevelle with the 11.5:1 402 BBC we ran dual 3 1/2's into one 5" single chambered FlowMaster and had it exit right in front of the passenger rear tire.....That my friends was a LOUD car!!!!

[Mater]

Todd, sounds like you're getting to that age with CRS like the rest of us old farts. I don't know how many times I've said I'm going to make a list but forget to. Maybe I should start a list to start a list.

i am only 23 and i have that hard core lol

i still find parts in the garage for cars i don't even remeber owning. like a distributor form a computer controld oldsmobile 307... only olds engine i remeber having was the 350 and that had the 4 prong HEI dizzy as it's still in the engine