dunno bout dodgy bit but,

i put GX head and carbs with exhaust youre talking about and it made a bigggg diffrence, mind you the standard gear had blown head gasket, but still i think youll be pretty pleased

it sounds like yours would be GX if its got that exhaust and SU's, easiest way is to see if the valve springs have a second set inside them (double valve springs)

Hey i have Hitachi SU's at the moment too... i guess these are OK these carbs, i was just wondering about a cheap alternative.

Oh yeh, a question ... Should the choke cable be hooked up to both carbies too ? (please excuse the obvious ?)

My choke cable only goes to the carby closest to the front, would it be wise to source an original setup and try and find the 'T-Junction' or whatever the original uses (if any)..

Cheers

Bigger carbs are only gonna make a big difference over 5,000 rpm. Which makes it worthwhile!

best place to get a proper choke cable for em is off a 180b sss cause they had twin su's, the flattop ones, but even this will be hard to find unless you got em from nissan i guess, i ran without chokes and it seemed fine

Datopower: Yes the choke is hooked up to both carbs. My setup has a block that takes both carb choke cables and one that goes to the switch. So that when you pull the choke on both carbs have the same amount of choke.

My carbs are the 38mm Hitachi "flat top" SU's. The head does have double valve springs which I am pretty stoked about. Does this mean its A12 GX or A15, I have looked thru the old threads and there was no clear answer. I must get something that can accuralty measure the liquid when checking the compression ratio as I reckon its kinda high.

Simon

GX!, maybe they were running diffrent fuel to pump fuel thats why its high comp

I have seen from Redline a single sidedraft Weber manifold I think for reliability and less maintenance this it pretty good, although nothing beats twin sidedraft Webers or Dellorto's or SU's for that matter. Just make sure you get them set up properly. I firmly believe you should go to someone who SPECIALIZE in tuning carby's especially on the dyno (important).

Quote:
One possibility is at the animal feed store, get a big syringe which is marked in cc or ml marks. Drill a small hole in a piece of plexiglass. Put grease around the the chamber and press the plate to it. Then you can measure how much water it takes to fill the chamber. This is also a good test for valve sealing. The water shouldn't leak out even after a few hours. If it does, the valves need refacing.

Also measure the dish of the piston in a similar way.