There are not that many alternatives. Of course, you can cut the stock manifold and make a true split unit by welding on an additional outlet, and then welding the ends of each half. You can also cut it in half, add a baffle with a hole in it, 1 inch or smaller, to mellow out the sound, add the outlet and weld it all up. You get to keep the stock heat riser with this set up. That is assuming you have the skill and tool box to do that kind of work. Most don’t.
So one alternative is to beat the bushes pretty hard and dig up a corvette factory dual outlet manifold. these are relatively expensive but are easy to install and you get the stock style heat riser. $$ are the issue her as I have seen them go for a few hundred.
Next, vintage fentons with the heat riser. Really hard to come by. Really hard. Vintage fentons without the heat riser. More reasonable and they come up for sale once in a while.
Aftermarket fentons currently on the market. I have seen them installed on quite a few motors they seem to be reasonable quality. No heat riser.
Don’t like the fentons, then Williams headers.
https://www.hillchevy.com/product/williams-exhaust-headers/Then there are the really crappy cheap sort of tube headers sold all over the internet. I think they are a terrible design. Don’t waste your time or money.
https://www.suncentauto.com/product...&utm_content=exhaustmanifoldsheadersReal tube headers are sold by Clifford. Prior to Jack Clifford’s death, Jack sold true long tube headers. I have run the same pair of Clifford long tube headers since 1983 or so. They also turn up on eBay and Facebook market place. These are application specific. They work good, sound great. One issue, they warp on the ends. So once they cycle a few times, you have to add some weld to the flange to build it up and make it straight. There was apparently a big brew haha when Jack passed away and somehow the guy who was making Jack’s Viper brand headers destroyed all of Jack’s jigs. So there will never be any additional long tube offerings from Clifford.
The current offerings from Clifford are “shorty” tube headers. Jack’s son-in-law Larry told me those shorty headers make the same power as the long tube headers but fit better. He may be right, I don’t know, but the truth is, when the Clifford headers are open, what a sound. Not cheap but they are real headers.
https://cliffordperformance.net/store/ols/products/52-0025-chevy-235-dual-outlet-street-rod-headersClifford Performance Engine Tuning VideoIf you are really handy, you can make your own tube headers. Here are some flanges
https://davisspeedequipment.com/pro...s-for-1937-62-216-235-261-chevy-engines/https://www.hellsgatehotrods.com/shop/chevrolet-early-6-cyl-216-261-exhaust-flange/http://www.headersbyed.com/__chevrolet.htm#EarlySo a few choices.
