Forgot my part # but after 9 years on the street they were all within 10lbs.....

I think the 1243 pac spring is a specialty spring for short install height. Can’t find anything like it on Isky site. $280 is not a bad price either.

Found my card they are part # 9385.....

Drag Week comes to mind.

Just FYI, I have ran Trick Flow TFS-16943-16 springs since 2013 on Edelbrock MW Victors with.674 Valve Lift. They are re-boxed PAC and I believe the 1200 series. The Trick Flow box says "by PAC". I pulled the heads apart a couple years ago (blew some metal out between 3 and 5) and when I checked the springs, was surprised how pressure readings (seat and open), didn't vary much from when I checked them when they were new out of the box. After fixing the head, I reassembled using same springs. . https://www.summitracing.com/nv/parts/tfs-16943-16

Cool. That’s an even better price yet. Thanks

I forgot to mention I've had and used a valve spring tester that shows Lbs. and distance when installing valve springs since the mid 1970s, on roller cam springs I shoot for .055 to .080 to coil bind on iron heads and from .065 to .085 on aluminum heads. I try to get the seat pressures within + or- 5 lbs. and shoot for between + or -20 lbs. open pressures by shimming or swapping the inner and outer springs to get what I want

I will check those best i can for coil bind and p-v, but thought if i set them up at 1.900 as they are spec'd by Pac, the pressures would be very close or close enough. I'm not removing the heads. I called Howards yesterday about the Pac 1200 and 1300 series springs and Eric tells me they never seen the 1300 spring last any longer than the 1200. He also said the 1200 is plenty for what i'm doing as some on he have said as well. Thanks guys