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Conference napalm::musclecars

Title:	Musclecars
Notice:	Noter Registration - Note 5
Moderator:	KDX200::COOPER

Created:	Mon Mar 11 1991
Last Modified:	Mon Jun 02 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	182
Total number of notes:	5467

119.0. "How to identify Holly carb?" by SALEM::NORCROSS_W () Wed Sep 01 1993 05:51

    I just picked up a Holly four barrel and Weiand 2P 180 high rise
    manifold.  My next step is to rebuild the carb and make it compatible
    with a mild (ie: possibly stock cammed 289 two barrel engine).  First,
    how do I determine the size of this carb?  I was told it is a 650 CFM
    but I can't locate any of the numbers on it in ads I've seen.  The
    numbers I've found are:  9834 1156, 388, 6R 4585B.  I would assume that
    a 650 would be too much carb for a relatively stock 289.  Can it be
    rejetted for lower CFM?  Where do I buy a good book on carb
    rebuilding/modifying?  If it makes a difference, the only other changes
    I plan for the car would be a set of headers and dual exhausts.  (The
    car is a '68 so it doesn't have cats.)
    Thanks, Wayne

T.R	Title	User	Personal Name	Date	Lines
119.1	It's a 600 cfm with vacuum secondaries.	TINCUP::MFORBES	It's NOT your father's Chevy Vega	`Wed Sep 01 1993 06:43`	13
	I just happen to have a Holley catalog at my desk today. Based on the first set of numbers that you losted, I found: 0-9834 (4160 series) Universal application, vacuum secondaries, non emission, electric choke, 600 cfm. You can not change the cfm rating of a carb by rejetting. The cfm rating is a function of the throttle bores, air horn, etc. I hope that this info helps you out. Mark
119.2	Is 600 CFM too big?	SALEM::NORCROSS_W		`Wed Sep 01 1993 07:32`	7
	Thanks, Mark. That agrees with what I have (ie: vacuum secondaries, electric choke). If I can't "de-rate" the carb, is 600 CFM too much for a 289? I believe I found a formula somewhere in this notes file that would indicate that as small as a 400 CFM would do the trick. Do Holly's go that small? Thanks again for the info, Wayne
119.3		TINCUP::MFORBES	It's NOT your father's Chevy Vega	`Wed Sep 01 1993 07:50`	6
	That carb should work fine on your 289. The nice thing about Holley's is their tunability. You can rejet, play with accelerator pump shot size and duration, and change the opening rate of the secondaries by changing the secondary diaphram spring. To answer your other question, Holley makes 4 barrels as small as 390 cfm.
119.4		IAMOK::FISHER		`Thu Sep 02 1993 11:29`	22
	Wayne, The 600 will work well on the 289 with a few basic mods. Go with a good dual plane intake, which will preserve bottom end power. This is especially important in an automatic trans, large car, 289 combo - where bottom end is important. Upgrade the ignition with a decent electronic unit, good coil, and wires. Headers are also a good idea, with a collector length compatible with an auto trans application. Duals with a cross over are also imperative. the stock valvetrain and cam should be ok with this combo, but you will want to think about hardened pushrods and pushrod guide plates if you retain the rail rockers. If you plan to rev the motor over 5 grand, plan on jettisoning the rail rockers, and absolutely modify the heads for screwed in rocker studs. Gears in the 3.25 to 3.50 range would also be nice, as a lot of the base Fords came equipped with 2.80 - 3.00 gears. Tom