I have a W5 tunnel ram with a duel 4150 top, was kickin around converting it to a single 4500, I dont think they made a bolt on top for this set up so some fab work is in order, what kind of gains can be expected from a swap from a ported M1 w5 intake to the tunnel ram?

your better off with 2 small carbs..
a single top..id expect the m1 to be better
cheapst

What about a split dom?

You plan on putting each half over one set of runners? Would you make a new top for that or use adapters on the top you have?

For the split doms I would build adapter plates to fit over the 2x4 set up on the stock manifold, I haven't seen the split doms yet, has anyone run them?

The rules we go by are single 4bbl or split dom no 2 - 4bbls, I was thinking there may be a torque advantage in the upper Rpm range with the tunnel ram , I all ready have it and its port matched to my W5s, was even thinking of a set of 500cfm 2bbl carbs, the w5s we run have the tops of the ports raised real high so with the tunnel ram its just about a straight down path to the intake valve, I have never ran a tunnel ram so dont have much info about them but from just lookin at it seems to me the air fuel has a long easy path to the valve

I think 2 carbs would be better but if the rules require one carb there's alot of guys using a ram with one carb, 340Rick and Bobsprofab have cars that fly with the single carb/ram combo.

We are seeing more tunnel rams or sheet metal manifolds with a single 4 on it this year running the same rules, any dyno info available on this type of combo, my power band now is around 5300 to 7k and trying to squeeze whatever I can within those numbers, I think the M1 I have now is a little shy on runner volume for best results

What class is this sounds HOT!

Its a mud class, under 500 ci single 4 or split dom,NA, no alu blocks, dot tire, it is a fun class , no 632s to fool with

Never seen a mud drag race but it sounds awesome like a tractor pull w/out the weighted sled.

if you center the 2bbl doms..over the front and rear plenum..
i think that will work.
that w-5 T/R has alot of plenum volume that i think a singel center'd would short change cyl 1-2 ,7-8.
best of luck let us know which way you go ..
and how you/it go's..
cheapst.

Yup, the 500cfm 2bbls, flow roughly about 375 cfm in comparison to a 4 bbl carb---so the pair is about equal to a 750 4bbl carb.

If your rpm is range is that high,, it seems to me the split dom's would work best.

I tried Daves idea of setting them sideways---did it on a two bbl motor i was messing with--only a single carb manifold however. I didn't see any improvement, but in theory it sounded good. I bet only a dyno could tell if them being sidways would make a difference or not. I think if you do it, just centering them over the runners will do just fine.

Thankx for the feed back, the split dom combo may have some potential, or fabing a single top may work, it seems that a single top will have to be raised higher up to straighten out the flow to the outside cyls, the combo we run now is a small port M1 W5 intake that has been modified by welding around 1/4" of alu around the top and side of the runners and hogging out a ton of material to match the ports, some one spent a ton of time on this one , the top flange looks like a dom pattern but with a 4150 layout< have to make carb gaskets form a dom pattern> then they spent the time to polish it all the way thru the runners, I run 2" open spacer on it to 1000cfm carb, as is the engine turns up super fast to 7k from around a 5300 hit on the vert , we keep short shifting and it seems the lower we shift the faster we run, we keep bumping up on tire size from 38.5x15 to 39x18 and the engine seems to handle the load, the tunnel ram would be a easy change if the benefits would prove worth it, one thing about my W5s is they didn't flow real big #s max but the low lift thru mid were real good and I think the long tunnel ram port will help torque, the tunnel ram has the same welding work on the runners but was not polished, it looks like the tunnel ram was never finished or used, I am trying to get a feel on how the tunnel ram config will effect torque curve, Big HP#s is not what I realy want its a longer torque curve