The theory behind it makes sense to me, and 266 bucks doesn't seem like that much in light of some of the other things I've done for my truck.

I was wondering if anyone has any experience or advice regarding these. I'd be looking at getting the split runner one, where the primary and secondary paths are kept separate right until the head, improving port velocity.

Basically, I'd be looking at getting this one. From looking at the others on this page, it looks like it should fit the factory carb, since there's another one listed for the 32/36 that's identical otherwise.

Anyone?

If anyone has played with 'em, might be Ted.

Don't use a split port if your are going to use a progressive carb. When the Primary opens 2 cyls will get good flow and the other two will suffer.

I looked at them for a while and just went with porting a stock intake.

Josh

Progressive meaning the secondaries don't open until after the primaries, right? Which describes the stock carb, darn it.

Why the flow problems anyway? Just runner length? And can anything be remedied by using the factory phenolic spacer with the baffles in front of cyls 2&3?

The Offenhauser intakes take one barrel of the carb and gives the air fuel to 1&4, then takes the other barrel and goes to 2&3. It splits the flow of the two barrels apart.

Make sense?

If that's how it works, that makes sense, but I read a different description.

"Offenhauser Dual Port intake manifolds feature completely separate runner systems for the primaries and secondaries. At low-load, the primaries feed the fuel-air charge through the smaller bottom passages at near sonic speed, improving power and efficiency. When the secondaries open, their charge goes through the bigger, cooler upper passages. Then, in turn, it is rammed into the cylinders when it encounters the high-velocity mix from the primaries. The result is better fuel economy and a 15-30 percent power increase across the whole rpm range."

To me, that sounds like it splits it evenly to all 4 cylinders, and the different runner sections deal with the primaries and secondaries, not different sets of cylinders?

the dual plane manifolds are partitioned off between the primary and secondaries(think of it as having 2 carburetors, one flowing into a primary manifold, and the other going into a secondary one), supposedly to increase velocity. i guess the idea is that since the fuel has less space to fill it will move quicker and stay atomized better on the way to the cylinders. maybe somebody else can explain better -- you can see the partion in some of the pics of the dual plane manifolds.

the C-series is a single plan(like factory) manifold. I've got one on my 20R hybrid and i have no complaints. i went from a 20R factory manifold with a 22R carb to the offy with a weber and it noticeably increased performance.