randya@pacbell.net wrote:
> You can still buy the Holley 450, I just got one about 4 months ago via mail
> order.
> My understanding is that it is much better suited to the Tiger than the 600.
> I don't have the address on hand, but I'll find it if anyone is interested.
> BTW,
> you can return the 600 to Rick as long as you don't run any gas through it.
The Holley that came with the LAT kit was NOT the 450, which is usually used in
pairs on double quad manifolds, but the 1848-1 465 CFM model. It included a "hot
air" choke which connects to the exhaust manifold 'stove'. I bought a brand new
one from Holley last year. I down sized the primary jets were by two steps
(0.001 inches/step in this range), and I put the lighter 'plain' spring in the
vacuum secondary (don't loose the ball check. There is no problem running this
carb on a low rise manifold, but you do have to get a 1/4 inch Boss 302 phenolic
spacer, with the PCV tube, to complete the connection, and re-plumb your heater
hoses that used to run through the 2 barrel base. I would suggest using the
Spectre anti-blowback check valve to prevent power valve blow-outs.
The problem with running this carb on a high rise, like the F4B or the Performer
RPM, is the PCV connection. since the carb has none, and even the 1/4 Boss 302
spacer is too thick for hood clearance, there is another trick. Go to a REAL
Holley carb supply house and get a universal vacuum secondary 600 CFM throttle
base, about $35. This has a PCV connection tube cast in, and the anti-blowback
check valve installed by Holley. If you've never run the carb, you can even
re-use the base gasket, or buy a new one. The throttle bores are 1/16 inch
larger
in diameter, as are the throttle plates, but with the thickness of the base, the
part of the throttle plate that sticks into the upper smaller bore is not the
full
diameter, and there is NO interference. You must be careful about the right
side
choke idle adjust screw. A little bending may be necessary to the support arm
to
align it with the stepped choke idle sector, and the adjustment should be made
to
match the stock setting BEFORE mounting on the manifold. or you can't get to the
screwdriver. This goes for even a re-build of a stock carb.
Works fine, no boggy, soggy points. Smooth acceleration with no flat spots, and
so hesitation when floored.
The velocity is higher, with the smaller bore, and the engine reaction much
quicker. If you have a highly modified engine, with rad cam, you might want the
600 cfm. The 715 is ridiculous over-kill, unless you have a full race 302
operating at WOT all the time.
Well, these are my personal opinions, and experience. I am sure there are
others
who disagree, as lots are using the 600, but I've tried both and am happier with
the 465 with my particular engine design choices.
--
Steve Laifman < Find out what is most >
B9472289 < important in your life >
< and don't let it get away!>
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