Here in NZ we have (had?) two styles of 4-1 extractors available.
1. "twin carb" - centre two pipes (ie 2&3) go over the two outers (1&4). To suit twin sidedrafts (Webers/Delortos etc)
2. "Single carb" - centre two pipes go under the outers. Suit std single carb manifold.

I've used both. Same pipe diametre. Don't think the single carb style would flow quite as well due to them needing to 'tuck' down a little tighter where they exit the head. Having said that I'd say they run well with GX set-up.

Heat shield does just that, always good to have. I say modify it it you have to but keep it or make a custom one. Just my 2 cents worth!

I would but the throttle return springs are mounted on the heat shield.

When I first got em I had no heat shield and couldnt figure out for the life of me where the return springs mounted.

If I had the skill I could make a replacement one that would maybe fit, in fact I could probably do that with enough time but I need new extractors to run the su's anyway, there's like 2/4mm gap between the fuel bowls and #1 & #4 exhaust primaries

lol i trimmed the corners off the heat shiel, but that was about 8years ago when i figured i could get another easy enough, i wouldnt be trimming a heat shield now, better to just not run one?

Yes, the A14T manifold won't outperform extractors, but it's still a good unit, good flowing, last forever, dont' leak, and a lot quieter than tubular steel headers.

I have an A14 exhaust manifold similar to the GX but single outlet.

The factory GX manifold is better than extractors. You can lenghten or shorten the down tube is you want to tune it for performance.

You can get big-tube extractors for the A-series that will outperform it at high RPMs, but those are even less likely to fit.

Heh heh yeah $75 US inc post is a great deal!!

you wanna sell the genies unfamilia?

my old genies fit, just trim the heat shield a little on the corners.

the thing of it is I paid $75 US for my exhaust manifold...including postage from AU


I got lucky