just a guess but dellows fabricate all kinds of different bellhousings to suit almost any gearbox to heaps of different engines, maybe give them a bell and see if they can help you out there?

AAAARRRRGGGGHHHH this is driving me nuts!
It runs spot on at cruising speeds and around town I can't fault it no hunting missing or anything. But if I give it a boot ful it is almost like a rev limiter cutting in at about 5500-6000rpm and sometimes it will rev right out liie nothing is wrong, What is going on? the plugs look like the mixture is perfect, I don't know what else to change, the fuel filter perhaps?

I am not sure what type of needle and seat I am using but I am using a brass float. it all looks brand new because the carb was rebuilt by a shop here in my local area. When I took the top of the carburettor off I checked the fuel level which was about 25mm deep in the bowl, I have a pair of F80 emulsion tubes and 180, 185 and 190 air correctors to test out and see what differences each combination will make, it just takes alot of time to tune eveything in and test every change but I guess it would be worth the time in the end when you have a sweet running datto.
One thing I had problems with was the idle air mixture screws at the bottom of the carburettor base on each side, I had a problem with them vibrating loose and winding themselves closed, I fitted a tiny O-Ring to each screw to absorb the vibrations and prevent them from moving

I have bought a new set of plugs and gapped them to .044", fitted 150 main jets and fitted an O-Ring to the idle mixture screws to stop them from vibrating loose again. I guess all that is left to do is see how it runs now.....fingers crossed

the carb was rebuilt and chemically cleaned before I bought it and before I rejetted it I blew all the fuel passages out and all the jets out with carby cleaner.
The bosche catalogue reccomends the HEC 715 coil for use on the bluebird series 2 and ferrol errol explained to me how to wire the dizzy up correctly.
I am starting to think that the plugs have gone off even though they look ok I think that by running a bit lean for a while and by having the plugs gapped to .044" it has caused the plugs to fail.
I can remember converted saying something similar about that

ok update number two
well the missing come back again so I am thinking it must be crook plugs as the coil is brand new and it doesn't get hot, I checked the plugs again and it looks to be running lean still so I removed the top of the carby to change the main jets to 150's and noticed the fuel level in the bowl was about an inch so it isn't flooding from a sunk float.
Then I thought i should check the idle mixture screws and then I got a shock, the screws had vibrated themselves to fully seated position which is why it was idling all over the place!
I will fit a new set of plugs and set lean best idle settings again and see if that has fixed it
This just keeps getting stranger, is there something i can do to stop those idle mixture screws from vibrating out of there settings?

Ok I Thought I would let you know a few more details of todays research and testing
First off the carb has a brand new brass float, the dizzy, leads and plugs are all new, the plugs were gapped to .044" as thats the standard gap for the Bluebird series 2 L series motor, which is what the dizzy came from.
But today I removed the plugs and regapped them down to .035" and the motor will rev like normal, well pretty close
I think it may be a bit lean as the plugs are a light pinky brown colour and power feels a bit sketchy and buzzy at full throttle once the revs start to climb over 5000rpm.
What is the correct colour for the spark plug? I heard that white is too lean, black is too rich but somewhere in between is about right.
I have a fuel pump with three tubes coming out of it, an inlet, an outlet and another tube I am not sure of, it has a tiny hole in the end of it and fuel will come out of it if I leave it unplugged, I am guessing it is a fuel return line, the motor came out of a C20 vanette
Thanks for all the help gang your all helpful legends

cheers for the suggestions, I will check the compression of all 4 cylinders and check the harmonic balancer too.
When it hits 4500rpm it misses quite bad and coughs and splutters but performance from idle is pretty normal idle is smooth at about 800rpm.
I have a feeling it could be a dose of crap ultimate 98 juice, I put $20 in her today and I can recall it started to miss soon after, my wife had a little 250 cruiser a while back and when I rode it home from the seller it had been sitting for 2 months, all seemed normal around 60kmph but once the motor reved up to highway speed the thing started doing the same as my datto. Turned out to be crap juice because it all went back to normal as soon as I filled it up with fresh fuel

well a funny thing happened today I was driving along and noticed a bit of a miss or flat spot at about 6000rpm under hard acceleration, I took the car home and checked base ignition timing, spark plugs, electrical connections and high tension leads, I took the car out again and now it starts to miss at about 4000rpm and won't rev past 4500rpm.
The engine is an A15 with a lumpy cam and running about 11.0:1 compression ratio. I am using a bosche HEC 715 coil with a datrats modified bluebird series 2 distributor set at 5 degrees base ignition timing and weber 38 dgas carb with F6 emulsion tubes, 50 idle jets, 185 air correctors and 145 main jets
It ran fine for past 2 weeks but now this issue has just appeared out of no where
very stumped on this one

I put my head gasket on upside down on my A15 a few weeks ago, thats my blonde moment!
Thats weird about the calipers making your wheels sit out differently though never thought it could be possible