You and Old School with your 572" RB's , my 517 B is just a 'lil small block by comparison!

yeah, I'm looking forward to trying it out, maybe this week-end, looks like I'll need to fab up a new Regulator bracket which will take me 3x what it takes to swap the manifold itself, lol

Any plans to take it down the dragstrip?

I'd like to get a back to back 440-2D vs 337 at Zmax, they're opening back up for Test n tune in a couple weeks.

Being an original R/T 4 speed Dana car I'm ( understandably) a bit reluctant to beat on it too bad like I did from the early 80's to mid 90's ( before they were worth more than 4 yrs of college tuition, lol) can't afford to restore it again. The motor belongs in an A body post car ( like it was supposed to go in). But a couple passes at Zmax should do both the car ( and me) some good for old times sake.

Is the 337 even available from MP any more?

I don't think so, haven't heard of one sold as new in quite a while.

I tell you it doesn't look like much but the taper from the plenum to the port outlet is very aggressive and seems well-designed for high RPM

Bobby if you ever bring that charger up here for me to work on you wouldn't ever get it back! I LOVE 70 B bodies. Ok back to work.

Ray - You still have yours?

I just purchased a new 337. I ordered it late December and it arrived in February.

Found this link online....might be worth a try for those who are looking

https://www.parts.com/index.cfm?fuseacti...Number-P4876337


Ron

Picture in that is actually a Stage VI RB 4500 intake, not the 337.

That's similar to the one like I bought from you, wasn't it Brad? The one Roger (Dr Air) Ported? Except that one was a 4150 flange.

Was going to use it but wound up putting the Chapmans on a Low deck instead.

What's interesting about the 337 is the as-cast head flange ports are small for a true MW, I think they did that in case somebody wanted to use it on a well relieved standard port.

The other thing is that with the ports opened up to ~1.3" x 2.6" the plenum to runner transition port opening is Huge by comparison, Mine is ported to almost the size of a business card in square area. That's a good amount of port taper across maybe only 5.75" of runner length. It would be a torque killer on 440 cubes but I'm hoping with a 4.300" stroke 517 with 11.7:1 CR it will pull very well.

Blues,

To be honest I have a TON of work in that manifold and it works awesomely so I doubt I will be turning it loose.

I'm not really sure what all the fuss is about with the 337, if you go to the tech Archives on Firefighters 572" (!!!) motor the Port matched (but still unported) 2d was only down 4hp (717 to 721) and 7 lb/ft (697 vs 705) to the 337, that's hardly a runaway victory (about 2/10th of 1 Per Cent) in my book. Dyno numbers are one thing, but roll-on part throttle torque (ie, "real world driving" is is almost always going to favor a 180 dual plane.

on a 750+ hp high RPM motor I would expect the difference to be more dramatic but up to 700 and especially with an automatic I don't think I would call the single plane a big (or even a noticeable) advantage, and at 470 to 500" I would think the advantage might likely be less noticeable or may actually be in the dual planes favor (in terms of average torque)

In my own case now I have a fully ported to fully ported comparison, I want to spend a day on the Chassis dyno and then hopefully Z-max at a Test & tune, but that will likely be after I swap back to the 833 4 speed. Ootb I didn't feel the 337 would have had any appreciable advantage over the max ported 2D so I never was too motivated to swap it.

It's not readily apparent from the pics but Larry did a lot of whittling on the 337, it should work really well. The ports are a good bit larger than before the walls between the runners are a good bit thinner, it's not just a polish job by any stretch for sure.

Looks like some educated porting to me, I think you chose well.