Carb suggestions for 455

[70f400]

I have a 70 firebird 3.43 rear gears 700r4 with your continental tight converter.  I have been running it with a FiTech for the last 3 years.  Tired of the glitches with this junk I want to go back to the Q-jet I built  with your help for a 455 with 044 cam and 6x heads. below are the specs .  What changes would you recommend for new motor.
Q-jet 1705 726.
 73 jets 44 rods idle tubes .039 idle down channel .059 bypass air .110.
New motor:
468 zero decked 10.7:1 HO intake KRE 290 heads
Initial timing 12deg 32 total all in by 3000, ported vacuum advance.
cam specs HR 236/244 .615 lift with hs 1.65 rockers. 114 lsa installed at 110
valve timing at .006
intake opens 32 btdc closes 73 abdc
exh opens 84 bbdc closes 32 atdc
These numbers are verified with degree wheel
Tanks Inc Tank with Walbro 355 pump 8n lines supply and return Holley regulator at firewall

[Cliff Ruggles]

Interesting as we have been getting a considerable amount of inquiries from folks who went to "electric carburetors" and want to go back to a Q-jet.

I've never been overly fond of any type of throttle body FI system and have exploited a few over the years only to ditch them and go to a carb and distributor with mechanical and vacuum advance.

That carb will take and like 7.5 PSI fuel pressure, that's the same carb I use and run that pressure on it, float at 9/32", .145" fuel inlet seat and small float.  I would upgrade to the HP accl pump as it has more pump shot capacity for the more powerful engine.

The 73/44's should be fine, and idle system close.  Test the carb in all areas then go in and make changes if/as needed.

I would order the "basic" kit on line, and we'll substitute the HP accl pump and .145" fuel inlet seat at no charge.  You may want to get idle tubes as well in case you need to go a tad bigger with them....tks.....Cliff

[70f400]

this may need to be moved to different spot on forum.  Car runs MUCH better.  will call monday to order some parts you suggested. One issue is the 700 r4 pressure cable is not adjusting correct.  the linkage for this carb was set up for  TH400 it seems to have the wrong stroke either adjust to were it will not drop down or it holds in gear to long and will not shift.  Any suggestions?

[Cliff Ruggles]

The TH400 carburetors have nothing for a TV cable.  The later Pontiac q-jets for Firebirds will have a hook up point as they used TH350's.  It usually works OK for the 700's and 200-4R's, but if it needs moved closer to the pivot point it's not too difficult.

The carbs with no provision take more work, we MIG weld material on them here and drill the correct distance from center and have even "slotted" a few to make the hook up point adjustable.....Cliff