SBC flywheel indentification

I don't know if anyone could give me an idea of what I have in a SBC flywheel for a manual transmission. it has the numbers 397..the 4th number is half missing at the bottom but the top of it has a curve like a 3 or an 8? the next two are 46 and the last number again is half missing again at the bottom but has the curve at the top too, like an 8...there is then a letter N at the end. It has a couple more short numbers on it but I didn't write those down..any ideas? I would like to know if it is a cast or steel flywheel, thanks

 

pictures? if it has cast numbers, then it's cast....

But good news, the N might mean it's cast of nodular iron. Bad news, it's still not steel

 

Sounds like a cast nodular iron flywheel. If the numbers are stamped in, it is steel, if they protrude from
the surface, it is cast.

 

the numbers protrude...if it is cast then would that flywheel be ok to run on the street in a 350-400hp sbc and muncie M22, or am I better off finding a steel piece? I can get pics if needed. I won't be beating or high revving this car as if at the dragstrip, but an occasional holeshot and the like is inevitable

 

Wow I must be young, never seen a cast flywheel. what years were they used?

 

The sculptured light factory "L88" flywheel was cast of nodular iron.
http://i66.photobucket.com/albums/h256/63mako/L-88Flywheel006.jpg

I think all other factory flywheels until the 70s at least were just cast iron.
That's why NHRA required something better in solid lifter chevy V8s.

 

RPM is the main problem, if you aren't revving it over 5000 you're probably fine...and you could probably go higher, too. Get a ****tershield and don't worry about it.

 

Jim, I really wasn't planning on continual high rpm stuff..you know how you would drive a street car..to compound the issue, I am doing as old school a car as I can and am using an old Ansen cast iron bellhousing..hopefully no problems will occur, but if it would be a safer thing I would buy a different flywheel. If I did that what is a good chevy one to look for ( stock or aftermarket) and what would one expect to pay as a fair price? thanks..

 

I would feel ok running a cast steel bellhousing and a nodular flywheel, as long I shifted at a reasonable rpm. You are putting a tach in it, right? what will you set the red line to?

 

Hi Jim..like I say it will be a street car and I won't be wild with it. yes it will have a tach, I usually shift by ear and feel and that is usually a lot less than a damaging high rpm, after all if I ruin it I buy and fix it. I love an old school SBC like a 283 or 327, however it may be wiser for me to do a 350 4 bolt main block with a steel crank, and use old heads, double hump of course, what that combo is safe to, I don't know, also has to have a solid lift cam. I know the nodular 9" cases are supposed to be the thing of strength, so hopefully the flywheel is the same as you say. thanks for the info guys..

 

if you're building an engine that needs a solid cam and steel crank, then you want a steel flywheel.

 

I do not mind erring on the side of caution if that is the phrase..or better safe than sorry!