Need help with Exhaust SBC to BBC…..

[KrausMotorSports]

I tried the search and not much came up. Is there a different location of where the exhaust exits between SBC and BBC. My 22c was originally a SBC. I bought it as a BBC boat but motor was out already and no exhaust. I have my eye on Stainless Marine exhaust and dry to the tip tails but they are straight angled. Currently building a nice 454 with the 731 Crane Came so Reversion isn't too big an issue but I prefer dry or close to it. So my question is will I have problems? The Stainless maring has the standard riser and I can add on the exhaust hose but another deal has popped up for the solid risers setup for Bravo. Any help appreciated! Thanks!

[yeller]

Conventional wisdom would say it won't work because a BBC is obviously wider than a SBC. If the tails you're planning on using end close to the transom, I'd be willing to bet you'll have to move the holes somewhat.

I had to relocate my transom holes about an inch when I switched from a 496 to a 502 because I was using a Q&Q and had no flexibility in the exhaust.
Now that I'm switching from the 502 to a LS3 I don't have to cut new holes, because I'm ditching the Q&Q. Without the Q&Q I'll be using enough hose that I can flex it over to line up to the existing holes

[KrausMotorSports]

Conventional wisdom would say it won't work because a BBC is obviously wider than a SBC. If the tails you're planning on using end close to the transom, I'd be willing to bet you'll have to move the holes somewhat.

I had to relocate my transom holes about an inch when I switched from a 496 to a 502 because I was using a Q&Q and had no flexibility in the exhaust.
Now that I'm switching from the 502 to a LS3 I don't have to cut new holes, because I'm ditching the Q&Q. Without the Q&Q I'll be using enough hose that I can flex it over to line up to the existing holes

Thank you!
I didn't know if it was a standard length with between the two. If I have dry tails made up it sounds like I could have them custom made using lightning headers. And what headers will work and clear the stock style hatch?

[yeller]

I should clarify that when I swapped the 496 to 502, I also switched exhaust. I went from stock to CMI headers. It is possible the difference in separation was due to the exhaust and not the engine. I'm not sure which was the cause.

I had a pic showing the exhaust spacing of the 496 and 502, but I can't seem to find it now. I will try and remember to get a measurement for you from the 502 and LS3 spacing, next time I am at the boat. LS3 is a different engine than a standard SBC, but I would think the exhaust spacing would be very similar.

Can't answer your question about which headers will work. Best bet would be to measure the amount of room you do have from exhaust ports to hatch and then you will know how tall of header you can use.

[yeller]

Found the pics.
496 spacing is 28 3/4" and 502 is 27 3/8".

[Carl C]

I had my tips relocated too after losing the 496 in favor of a 525EFI. It's not a huge deal to have a good glass guy do this and repaint the transom. Don't cut the new tip holes until the engine and exhaust are in place so you can get perfect alignment.

[KrausMotorSports]

I had my tips relocated too after losing the 496 in favor of a 525EFI. It's not a huge deal to have a good glass guy do this and repaint the transom. Don't cut the new tip holes until the engine and exhaust are in place so you can get perfect alignment.

Measure Twice cut once!. I know lightning marine can make a custom set if need be. Sometimes I know some companies can cut and reweld the exhaust to fit your current setup vs. changing the exhaust current location. I'm in the process of putting a very healthy 454 together for my 22C. But I also have a lq9 sitting in the corner ready for a rebuild. Which could make essentially close to the same power. Hmmmm maybe later down the road.

[KrausMotorSports]

Found the pics.
496 spacing is 28 3/4" and 502 is 27 3/8".

Awesome! Thank you Yeller! I'll check with what I have this weekend when it's daylight. I leave when it's dark and get home well after dark.

[CHACHI]

Found the pics.
496 spacing is 28 3/4" and 502 is 27 3/8".

What great diagrams..even show the water inlet for the water pump

Ken