In a message dated 02/07/2000 3:53:37 PM Pacific Standard Time,
Laifman@Flash.Net writes:
<< I believe that the 260 and 289 heads are very close together, although the
later
ones had a larger exhaust valve. The REAL question you should be asking is
whether the even larger exhaust valves of the aluminum heads will hit the
piston,
with what maximum lift cam. And all these aluminum heads are reputedly
thicker
than the iron originals. So, what is your clearance on the inside rear valve
cover and the fire wall?
>>
Steve-
I think your point re: valve interference is right on target. Another
question I have in a 260 application would concern volume...I think the 260
casting is 54cc and, if I'm not mistaken, the 289-302 aluminum heads are in
the 62-65cc range, so new pistons would be in order, unless you want to mill
your new heads.
Also, some of the aftermarket heads have different exhaust port
configurations and locations, which poses problems with header selection
(nil) and header clearance (ditto). I believe the Motorsport and Edelbrock's
are dimensionally identical to the stocker, cast iron heads, so they should
work fine.
I am interested in this subject, because when my motor comes out, I will
upgrade to whatever heads work best, along with roller rockers.
On the 260, I don't see any reason to spend the money on the heads. By the
time you replace pistons, cam, machine work etc., you can go a lot faster for
less money by simply dropping in a "crate" 302. That's the solution I came up
with, keeping my stock, original 260 on a motor stand for that day I choose
to go "authentic"...don't think that will be any day soon!
Mike
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