Question about adding 3" spacer/riser to exhaust on 7.4L

[tpenfield]

As per my extended swim platform thread, I am considering adding a 3" spacer to my current exhaust setup, which is pretty much factory standard for 1996 - center riser manifold with stainless steel elbows.

I measured the height of the elbows per the Mercruiser procedure:



I got the 'a' measurement of 20.5", the 'b' measurement of 5.5", leaving the 'c' measurement of 15" . . . all of this with no people load. I have taken some measurements with people load (8-9 ppl) and it looks like the stern is down about 3-4" from the no-load condition, which would put the 'c' measurement at 11-12", just below the Mecruiser spec of 13" with "maximum load aboard".

I'd like to add a 3" spacer to get back to the Mercruiser spec.

Question: I see kits for the 3" spacers that go between the exhaust manifold and the elbow. I don't see any 'kits' for the exhaust tube portion that goes from the elbow tip down to the y-pipe. I would assume that piece has to be 3" longer than normal due to adding the 3" spacer.

Any help with the various parts for this? Serial #'s are in my signature.

 

[Bondo]

I don't see any 'kits' for the exhaust tube portion that goes from the elbow tip down to the y-pipe. I would assume that piece has to be 3" longer than normal due to adding the 3" spacer.

Ayuh,..... Hi Ted,...... Ya just get a 3" longer rubber coupler for that joint,.......

Exhaust hose, sold by the foot,....

 

[tpenfield]

Ayuh,..... Hi Ted,...... Ya just get a 3" longer rubber coupler for that joint,.......

Exhaust hose, sold by the foot,....

Yes, thank you. :thumb: I was thinking the same, once I found an extended elbow part set that was $500

i think I can get some 4" exhaust hose for not too much $$$.