[6pack] 1970 tuning questions

[Kendall Larsen]

Hi List,

I put a used 1970 engine in my 1974 TR6 not too long ago. I installed it,
carbs and all, with my 1974 exhaust, and it runs pretty well with no adjustments. Recently I
got around to trying out my wideband O2 sensor with it and it shows
that it is running lean. Due to a miscalculation of the O2 sensor size and the proximity I can
only get readings from the rear carb since I'm still using the 1974
exhaust.

The AFR ranges between 14.1 (0.96) -16.8 (1.14) Tending towards 16 lots
more often than 14. Pulling the choke didn't seem to do too much to
richen it while cruising. What AFR should I be shooting for as far as
just casual driving around is concerned?

Is this so lean that I should be worried about burning a valve? Any other problems beyond generating excessive NOx? 

I tried to use my needle adjuster tool and discovered that the 1970
carbs
don't appear to have adjustable needles. Is the adjustment handled by
moving the jet from the bottom or is it more effective to swap needles? 

It occasionally starves for fuel when cornering to the left, like when
making a left turn from a light and accelerating. Is this most likely a
float height problem? 

As far as I know the engine internals are all stock, with ~100k miles, only mods are an aluminum flywheel, and electric fan.

Thanks,
Kendall
Camarillo, CA