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Thread: Pro-Jection 4D Throttle Body

  1. #1
    Fast Ted Guest

    Default Pro-Jection 4D Throttle Body

    Can anybody tell me the bore size of a 900 cfm Pro-Jection body? I bought a used system off eBay a couple of months ago and now I'm trying to make it work. The one I bought has 1-1/2 inch throttle bores and has 12R-11157B on the side. My sixty foot times are same as with the old 800 cfm double pumper but everything else has slowed down. I'm thinking I got took. Since it's too late to return it and the pump and ECU are the same, anybody know where I can find a 900 throttle body? Can I bore mine? (25 yrs machining exp.) Any help is greatly appreciated. Thanks.......Ted

  2. #2
    Join Date
    Dec 2009


    Quote Originally Posted by Fast Ted View Post
    Can anybody tell me the bore size of a 900 cfm Pro Jection body? The one I bought has 1-1/2 inch throttle bores...
    The 900 cfm TBI throttle body has 1¾" bores. The 700 cfm TBI throttle body has 1½" bores.

    Can I bore mine? (25 yrs machining exp.) Any help is greatly appreciated. Thanks.......Ted
    I've never bored one out, however, I have replaced my 900 cfm throttle blades with Holley #26-97. (My ported TBI to MPFI throttle body.)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS T/W 11R 205 heads, 232°-244° duration/.623" lift/114° LSA camshaft, 12:1 C/R, TFS R-Series FTI ported intake, BBK 80mm T/B, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 200A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, -6AN fuel system plumbing, Walbro 255 LPH pump, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, B&M Hammer shifter, FPP aluminum driveshaft, FPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 M/T Street Comp tires.

  3. #3
    Fast Ted Guest


    Thanks Danny. Mine was not only a 700, but it had 3 correct #250R-100AA (65 lb.) injectors and 1 red capped injector of unknown flow (250R-51). I ordered a set of 1-11/16" throttle plates from Holley, Bored the throttle body holes, and installed a set of 250R-123AA injectors. It sounds great in the garage! Next Friday night I'll know for sure. Thanks again,Ted.

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