I have heard rumors that us folks with the older blocks (68-86) can somehow physically modify our blocks (by drilling or something?) to where we can support non retrofit hydraulic roller kits... It involves basically making it so the lifter bores are no longer circular somehow... this way the lifters don't spin in the bores, wrecking havoc on the valve train, but without the need for the pesky link bars.
Has anyone heard of this, and can you tell me how to do it, or what is involved? I'd love to be able to buy a ZZ4 cam for my 327 for $30 on ebay and then some stock GM roller lifters from an 87 & up engine.

I've heard you can somehow
get the older block to accept the spider that bolts into the newer blocks,
that holds the lifter retainers in place, then use all the new roller stuff.

i would love to see more more replies on this topic.

Seriously, what would prevent me from drilling holes in the center of my lifter valley, and attaching the sheet metal "spider" and lifter retainers seen here?

http://cgi.ebay.com/ebaymotors/Chevrolet-V6-4-3L-Roller-Lifter-Tray-Spider-Retainers_W0QQcmdZViewItemQQcategoryZ33614QQitemZ7 991071682QQrdZ1QQsspagenameZWDVW

(I know this is for a V-6, but I've seen them before for V-8's on Ebay)

Let's face it, the only reason we have to use the retrofit lifters with the little bar is because the lifters would otherwise spin in their bores, causing catastrophic engine failure. Why not instead of paying all of the money for retrofit lifters could I just go to my junkyard, find an 87-97 V-8, get the spider and lifter retainers for five bucks, and then put in a ZZ4 cam and factory rollers?

And another question, is there a difference between roller cams for 68-86 V-8's and those for 87-97? If I DID have the retrofit lifters, could I put a ZZ4 cam in my car?

And what other mods would be necessary? Hardened distributor gear? Fuel pump pushrod? Cam button?