Old days is before 1974. With your 351 cleavlend, it came with a 4 bolt main
and is rated for 300+ hp. The newer engines, ones that has ECM's can
increase hp by simply installing a new computer chip. On Cummins we did this
several times to trucks, hooked it up to the computer and increase hp in it.

Ed
"Jack Goff" wrote in message
m...

"ed" wrote:

In some engines you can obtain a higher horsepower by inserting a bigger
micro chip. I know they do this on the big rigs via the ecm. Dont know if
this is how ford does it or not. Back in the old days you would have to
get
a bigger cam, run solid lifters and machine the head to obtain that kind
of
horsepower.


I guess it depends on what time period you define as "the old days", but
it
wasn't difficult at all to get 300hp in the late '60's through '71. My
1970
M-code 351 Cleveland 4V was factory rated a conservative 300hp with cast
iron exhaust manifolds and hydraulic flat tappet cam and lifters. The
factory cam had a slight burble, but no big lope and it had great vacuum
(something a large, lopey cam does not).

It *did* have 11.5:1 compression, so it required premium fuel in 1970!
Unfortunately, today's premium in nowhere near as good... so it's octane
booster or racing gas when I drive it now.