The big mercruiser manifolds with the 6 bolt riser? They no longer exist. The wet joint was too big and leaked. This manifold is the reason merc started using gils. They support a lot of power, but will wreck your engine. They make good wall hangings. You need 2 modern sets of exhausts. And please, don't resurrect old threads. Start a new one.

MT you going to stay dual plane? Something tells me you likely will. Those stock intakes work well and one of the most even EGTs dual planes I've tried. This goes bac ka few years but I don't see any drastic changes since either. Something to be said about the original look also. Just my opinion. When you acquire the Excalibur anyway?

2005ish

nothing like bringing back a 12 yo thread,lol.

Tks Mike. That would explain the Excalibur. I never even looked at the OT. I was beginning to think I missed something in the last few months I haven't logged in much. Wtf. How did this happen??

By the way. The 425hp I was speaking of, was neither a GEN 6, nor a GEN V. It was a Mark IV mercruiser high performance crate long block. Basically the same engine as the 454 /420hp Merc.

You still run those short blocks right?

Nah. Not those . But Similar though . Same blocks, same cranks, but Manley H beam rods with arp2000 bolts, Arp main stud kits, JE blower Pistons.

Simple. A guy looking for a set of those extinct manifolds found this thread by Google searching 420 exhaust. So he joined OSO and resurrected a 12 year old thread not realizing it was 12 tears old to try to find a set. I bought a set at a boat swap meet in 1993. 30 bucks. Already extinct. Went to Trenton marine to buy tails. They said 750. I said nobody wants them. 100. They said 750. I said throw them out and threw the manifolds out.

My 311 had those manifolds when I purchased it over 10 years ago. Bought the imcos from Teague at the time, I notice now that they don't list the TRS tails available anymore.....I can't believe i'm saying this but the TRS stuff is getting more obsolete every day. Doesn't surprise me that he would reach out to OSO to find something.