do they make those?? i cant seem to find any and i dont want to spend the money on o-ring types and getting everything machined.

thanks!

I just bought a set at an Advance Auto...Fel Pro Im pretty sure. I had them look up a 70 Chevelle, 454...it listed both a single spring, and a dual spring option...I had them order the dual spring, and they worked fine. I think I still have the box they came in at the garage, when I go there later this morning, I'll post the part # for you.

Victor-Reinz has umbrella seals for BB Chev., part number is B45296. Seal OD is .870".
Dana's info says this is a direct interchange to Fel-Pro #SS72513, which is the number that they specify for BB Chev with dual springs.

Not a machineist so I may be describing this wrong, I believe you can turn down the guide and use a seal with the same outer diameter as the guide to insure it doesn't interfear with the inner spring. I don't know if this weakens the guide or sets you up for other problems but have seen it done many times...

Alan, engineguy has it right, fel pro # is SS72513

Alan,
The id of most double springs is too small to use anything but a positive seal that requires machining the guide. For example, the Comp Cams 924 spring, used on most big block cams, measure .697" inside. The Fel Pro and Victor seals that are .870 wont work :( If you want to do it right, machine the guides for the good seals.

I'm going to be using Comp 933 springs,the guy thats doing my heads is using the positive seals also.

Moral of the story: Positive seals are always the best solution for high performance heads. Have your machine shop machine the guides for positive seals while they are doing the rest of the head prep and be done with it.

darn... about how much would machining in postive seals cost? i was wishing thats a way that ic oudl get by without dual springs... i guess i will buy stronger single springs...

You can buy the tool to do it yourself from Crane for about $50 if I remember right. Put in your drill and go for it. Just use a shim under the tool to keep from gouging your heads. It took me all of about 30 min. on my heads because they were already disassembled. If your heads are still at the shop, have them do it. It won't be much.

Troy.