Tom,
Putting 289 heads with larger 1.79" intakes on 260's was apparently common
practice back in the '60's. Mannel's book reproduces a Ford ad for the
"Cobra Kit", which was basically HiPo heads and camshaft, and recommended
for use on 221, 260, and 289. Also, Gordon Chittendon's book "Sunbeam Tiger
Performance Tuning, considered by many as the "bible" for hot-rodding the
Tiger 260, shows a picture of a 289 head with 1.79" intake valves being
prepared for use on a 260. On page 97 he writes: "If using the standard
flat-top pistons, and the LAT-20 camshaft and the 289 c.i.d. cylinder heads
with the larger 1.788" intake valves, the intake valve area will have to be
fly-cut in the stock piston. This is not required if the LAT-20 camshaft is
used with the stock 260 c.i.d. cylinder heads and the stock 1.67" intake
valves."
I'm pretty sure that fly-cut pistons would be equally necessary on a 4.0"
bore 289. I'm not sure how much bigger than 1.79" the intake could be made
and still clear the 3.8" 260 bore, but clearly 1.79" intakes are OK.
Bob Palmer
rpalmer@ucsd.edu
robertpalmer@paulhastings.com
rpalmerbob@adelphia.net
|