1967 - 7027240 - Fuel Inlet Upgrade - Needle and Seat Kit

[Cliff Ruggles]

Never flow tested this modification, but removing the choke flap picked up a few hundreths of a second at the track, back to back testing, so it does help if your engine needs more cfm's?.....Cliff

[65WildCat]

Went out to the barn and fired up the old cat the other day and the new '67 7027248 with your blue accel pump added sounds great... At idle only of course... Can't wait to road test it... Come On Late Spring......

I found a next, next generation stamped on the body 7027248 without the pressed in circle tag, yet can still see where it might have been in the mold... Big differences or at least in the top of the carb.. This one has the slotted secondary air flaps w/discharge holes even with or slightly above them and the adjustable idle air screw in the top behind the vent... Could be that someone changed the top to a Early Pontiac or they were really experimenting up to the '69 change over...

Northern Cabin Fever and now getting ahead of myself ---

I have a 7044270 I'm thinking of running on this old nail...  Haven't opened it up yet, but what would a good primary jet size and rod selection be for this application.... 425 .040 over - Stock Type Cam - MSD Spark, Pertronix Point conversion, Cold Ram Air Cleaner w/4" Ducts running to the engine bay corners - not direct air ram, Auto Switch Pitch 400 Trans - 2 1/2" dual Exhaust w Big Block Flowmasters - 3.73 Rear with 33" tires...

Jim

[65WildCat]

I forgot to mention I would be using a 1/2" Phenolic 4 hole spacer.. If that makes a difference in the jetting? Also when adding the '67 Primary Shaft, do I just use washers and shim the choke side hardware to make it work correctly?

Thanks Again,

Jim

[Cliff Ruggles]

Difficult to say on the jetting.  The old intake should have had an exhaust crossover system under the carburetor, nearly as I can remember?  If it is blocked off and a spacer/insulator added, sure, jetting will have to be stepped up some to compensate.

We also have less energy in modern fuel, which also contributes to jet requirements.

The SD carb will accept an eletric choke, and they are very good units.  It may be somewhat lean for the application, as they were produced in the mid-70's and used with EGR valves, hot thermostats and other emission control devices.....Cliff