Hot Rods Stock Valves with Aftermarket Springs on Low-Buck Build?

I'm building a low-buck AMC 360. It's getting a mild hydraulic flat tappet cam and I'm upgrading the springs to some with 115# on the seat and 280# open (stock springs had 80/180). I'm going with new retainers and locks as well.

Anyway, the heads have been gone through at some point; valve job is fresh and the valves - 2.02" and 1.625" - appear to have been replaced, but they're just OEM replacements - 3/8 stem and single groove for the locks.

A few of the exhaust valves had some pitting near the head, but I found some Sealed Power OEM replacements that I'll use instead.

I've generally replaced OEM valves with new stainless ones whenever I go through and engine, but I'd rather not doe it now unless it's idiotic not to. Curious to hear your thoughts.

I realize valves aren't that expensive, but this is a backup motor and I'm running out of time and $ to have the car ready for an upcoming race.

Thanks

 

Sure, why not? Back in the day upgrading the springs with stock valves was the norm. While there are performance gains to be had, in most cases they're not huge.

 

I use springs that match cam specs
Valve material?
Whatever works.

 

Amazing! That's EXACTLY what I was going to post!

 

Not like 350 to 400 on seat,
Shimmed many stock springs for
.500 to .520 lift in early 80s when No $

 

Ditto, ditto ,ditto unless you’re getting crazy with the cam and engine speed,
etc.
Dan

 

Like Anthony, I use springs that match the cam...sounds like you might be getting carried away, unless your idea of "mild" is different from mine.

What does the cam grinder recommend you use?

and yeah, new mild cams and used valves (in decent condition) get along fine.

 

Cam is quite mild - .491/.494, 224/228 @ .050. It's a budget endurance race build, so rev limiter will be set at 5,300 or so.

Thanks

 

These are 1970 291C castings with small combustion chambers and screw-in studs.

Thanks

 

It's a custom cam from Bullet Cams. I'm using their springs, retainers, and locks that they recommended for the cam.

Thanks

 

Does the AMC use .904 diameter lifter IIRC it does. I believe you’ll be fine with what you have.
Dan

 

Yes, they're .904.

Thanks