Annular vs downleg

[Shaker455]

Hey Herb,
Thanks for posting the pics and your intended use.

The throttleshaft has to be addressed as that will directly affect your tuning and performance.

I would fix that first and then try to retune as there's many things you can do to that carb.

Seeing it's an 850 mainbody with a rear squiter boss it can be converted to a DP Mech sec and if you wanted a slightly smaller carb it could be achieved by changing the booster to annulars.



Typically with downleg 850's they have a weak signal at part throttle/cruise and I resolve this with jetting the transition circurt.

Annulars have a good signal and do not require this but the trade off is they take up more CFM, if you were drag racing I'd lean towards downlegs.

I haven't had a choke on any of my cars for years and if the carb is tuned properly it will not require it....ran my car into Dec last year until they salted the roads!

More times than not the flap will not be opened fully and cause tuning issues

You can PM or email for prices.

Frank,
I'm glad to hear you had good results with the HP's,

Many come my way overly rich, difficult to tune, and lack of needed vacuum ports for street use.

When I build a new HP from scratch I use a baseplate with vacuum ports and proven Holley metering blocks that feature ported vacuum for engines that want to ultilize vacuum advance.

I add the ported passage into the HP mainbody which has none out of the box.
Jeff