pedec

Having my 427 motor rebuilt and wonder if changing out the factory manifold for the hedman headers that are build for stock sidepipe cars are worth it. I also bought some new big block stock mufflers from ecklers but they look just like the small block ones. So I was wondering if it worth changing to headers if mufflers are the problem. Is there a difference between stock small and big block side pipes. Thanks for any help.

7t9l82

i have used them on other corvettes i had and liked them. but there is the contingent here that won't like them. to me , headers are always worthwhile.

qwank

I have them on my small block and like them. I think you would benefit more from getting larger than factory mufflers though.

pedec

So I guess my other question would be the factory small block sidepipe have 13/4 baffles do the stock big block pipes also have only 13/4 baffles or are they bigger. My motor getting built should be 475-500hp and I am afraid I bought the wrong pipes thinking stock big block pipes had bigger baffles inside. Thanks for any help.

qwank

I built my own side pipes. 2.5" into 3''. plenty of flow and a lot cheaper than factory style mufflers:

MalibuVLX

I have a SBC 406 w/ factory side pipes but wanted a different sound. I went w/ the Allen's Chambered side exhuast kit, purchased some ceramic shorty block huggers and modified them to fit under the factory fiberglass and chromed covers. I went w/ the 2.5 I/D which is 3.0 O/D, so a little modification to the brackets that mount to the frame was needed for clearance. Headers were est $150, exhaust was est $300 and had covers already. Can barely see the pipes under the covers. You have to get down on the ground and almost look under the car to see them.

pedec

Thanks for the help. Got hold of sweet thunder and they helped me out a lot. Going to run stock manifolds with there hi performance 21/4 baffle sidepipes. Which should let my 427 breath a lot better than the stock pipes which are only 13/4 baffle. Hoping ecklers will let me return the factory ones.

qwank

Let us know how you like the sweet thunders. I was going to buy just their mufflers and make my own pipes to hook them up to the hedmans. the only reason I didn't is I was afraid the mufflers would hang below my aftermarket covers.

pedec

It sounds like they should mount exactly like the factory ones I hope. But I will let you know. I am also going to dyno compared to stock pipe to get idea how much differance there really is.