PUSHROD LENGTH

[thos25]

My son is rebuilding his 65 Ranchero; 289/4spd. His machine shop installed Chevy valves in the otherwise stock heads. He has a COMP CAM Nostalgic cam;#31-670-4. This is a hydraulic cam with the same grind and specs as the old HI-PO solid cams. My concern is pushrod length. I wonder if anyone has had experience with this and if so what length pushrods did you use? Does the use of the larger CHEVY valves dictate a change in the geometry of the valve train and therefore affect the push rod length or not?
Thanks to All who answer. Kind Regards, TOM

[comethead]

It would be a good idea to actually measure with an adjustable and go from there.
http://www.compcams.com/Pages/417/valve ... metry.aspx
http://www.lunatipower.com/Tech/Valvetr ... metry.aspx

Joe

[Lip Ripper]

Isn't the 65 head adjustable rocker style? The main thing with the 289 is to use the hardened push rod since they are guided by the slot's in the head. It is easy to tell if your push rods are hardened. Run the edge of a flat file over them. If it roles off, they're hardened. If it digs in they're the later style that need the little skirts on the rocker to keep tem in place. Is my memory correct guys? Your making me think about things from 30 plus years ago but I think the ***** valves just had a little larger diameter on the head of the valve.

Stacey

PS; as long as the lift is below five hundred you won't have to worry about pulling the pressed in studs loose.

[comethead]

Your right Stacey. Early 289 to 1966 used fully adjustable valve train with the pushrod slots in the heads using hardened pushrods.
Late 66 Ford went with rail rockers for valve train alignment. Longer valve stem tips and round holes in the head for the pushrods and non-hardened rods.
Then in 68 Ford began using the non-adjustable "positive stop" rocker stud with the rail rockers. Torque'em down and your done.

Joe

[Rocket989]

IIRC the Chebby valves are a little shorter. Best bet is an adjustable pushrod as noted, one solid lifter, and a light spring! I'd also make sure they kept installed height correct on the springs!

JH

[popscomet]

Isn't the 65 head adjustable rocker style? The main thing with the 289 is to use the hardened push rod since they are guided by the slot's in the head. It is easy to tell if your push rods are hardened. Run the edge of a flat file over them. If it roles off, they're hardened. If it digs in they're the later style that need the little skirts on the rocker to keep tem in place. Is my memory correct guys? Your making me think about things from 30 plus years ago but I think the ***** valves just had a little larger diameter on the head of the valve.

Stacey

PS; as long as the lift is below five hundred you won't have to worry about pulling the pressed in studs loose.

your memory is pretty close ,STACEY....POP use to race alot on the top end ,in my 67 302 4bbl 4speed fairlane,after a long ways at way over a 100 plus mph,when I came to a stop or slowed down to a normal speed ands rpm's,I always had ONE lifter that rattled,I'd take the VC off and take a copper hammer and whack the crap out of the stud and knock in back down and fix it,,it would depend on how long it was held to the floor,but after A good wacking it was always good to go ,best I recall it was always on number 2,,that was one traveling ass fairlane,it didn't bother me if you had a vette ,a firebird or a mustang or a 1913 hupmobil,,the race was on,that little fairlane was as smooth and solid feeling at 120 mph as it was at 30 mph,and back then pop was scared of GLENDA and GOD ALMIGHTY,and thats all..had a pair the size of bowling balls,pop

[Tristan]

My son is rebuilding his 65 Ranchero; 289/4spd. His machine shop installed Chevy valves in the otherwise stock heads. He has a COMP CAM Nostalgic cam;#31-670-4. This is a hydraulic cam with the same grind and specs as the old HI-PO solid cams. My concern is pushrod length. I wonder if anyone has had experience with this and if so what length pushrods did you use? Does the use of the larger CHEVY valves dictate a change in the geometry of the valve train and therefore affect the push rod length or not?
Thanks to All who answer. Kind Regards, TOM

I have the same cam. I used the stock pushrods, lifters and valves.