So having a niggling prob with my offroad toy.
She is an 87 classic 3.5 v8 Auto.
I have fitted her with SU carbs which were stipped, cleaned and fitted with new floats and needles before being fitted.
Fuelling is via a redtop facet with a fuel regulator up front.

Starts fine with full choke

so once warmed up at idle in park, the revs sit at about 1200 revs, and will rev cleanly from there.

When i drop it into drive or reverse the revs drop off to 500 ish, which is too low. I have to feather the throttle up to about 1000 rpm then its fine and pulls away. If i put my foot down hard from idle it'll stall.

I tried upping the idle via the stops on the throttler assembly to 1500 when in park, thinking this would take it to about 800rpm when dropped into gear, however it still sits at 500 ish???

The only way I have found to solve the prob, is run with a tiny bit of choke, as that bring the idle up when in gear to about 800rpm where I want it.

Any ideas to sort it properly much appreciated.
Thanks

The idle air mixture is wrong. It is ticking over too fast at 1200RPM. You need to adjust the mixtures if they don't pick up from 500 rpm. Depends which SUs they are. Do a search for SU carb setup. Mixture is set by turning the hex nut under the carb on most then lifting dashpot about 1/16" with the lifting pin. If engine speeds up it's too rich. If it speeds up then slows back down it's not far off. If it slows down it's too weak. Bit of a knack to it actually. Balancing them up is quite an art form.