TechnicalPelican

Just recently picked up a 77 Corvette with a full side pipe system using the hooker headers with the 4 inch collectors. i have been thinking of an LS swap, but I don't want to spend extra for custom headers and I'm wondering if the clearances would allow me to weld a new flange on the hookers and relocate the pipes to fit the pattern on the LS heads. I'm also wondering how much I would have to cut to keep the headers exiting in the same locations so the pipes bolt up right if anyone has ever attempted this.
Ethan

Corvettedave02

This is the main reason I went with a sb 427 rather than the LS. I really wanted the sidepipes. Iron resurection did an episode with a 68 LS and it looks like they used the 4" pipes but custom made the headers.

wwiiavfan

Several companies have LS sidepipe headers for C3's with Doug's or Hooker style sidepipes, so you aren't really buying a custom set anymore.
But, I get it, even the off-the shelf ones are pretty pricey.

Kevin_73

You also need to consider where you mount the oxygen sensors. The only place they can be mounted and stay hidden is on the inside lower part of the pipe, but you run the risk of fouling the sensors with water condensation if they aren’t mounted in the top half of the exhaust.

Bikespace

Pics? Have you driven the car much? If it doesn't have three pedals, fix that first, and you may find it doesn't need an LS.

My side pipe 80 will likely always be an SBC, but my 79 may get an LS soon. No reason not to do an under car exhaust with an LS, as even stock manifolds flow well on them. You can easily sell the sidepipes.

Corvettedave02

good point regarding the o2 sensor Kevin. I agree there is no perfect place to mount them if they are hidden. Mine are mounted in the collector but angle down 10-15 degrees to miss the frame. This is not ideal but did work. I did fouled one when tuning and they are pricey.