I was looking this over again and remembered. If you add the timing numbers together then add an additional 180 you will get the advertised duration for the cams. So the old LDB was a 271 duration cam. I had the ISKY cam run on a cam Dr. and it shows the @.050 duration to be 198.3 intake and 210.1 exhaust with .345 intake lift and .377 exhaust so it doesn't match this catalog. I wonder if the grind is custom or if the LDB changed over time.
Originally Posted By: stock49
Originally Posted By: Hillbilly
The Isky LBD has a lot less duration and lift than would be common now so I need to pull the forged steel cam from my spare 248 at the farm for a core to regrind at Bullet racing cams.


Hi Hillbilly . . . nice find. To bad about the pond in the oil pan :-(.

I see from the thread over on HAMB that you're looking for specs on that Isky regrind. I have the 1956 catalog. Chevy and GMC cams are found on page 59 and 60:



Unfortunately, back then there was nothing but advertised (valve event) durations - so there is no telling what the .020/.050 specs are for modern comparisons.

Another thing interesting about these old catalogs is the breath taking prices. $59 was a ton of money in '56 - adjusted for inflation that is well north a $500 in today's money!

regards,
stock49

Last edited by Hillbilly; 02/12/20 10:51 AM.