I know it's a flat tappet block, but i read somewhere you can tap and bolt the retainer (spider) in there, here an auction that explains a littleRETRO ROLLER
I have the cam lifters pushrods and retainer laying around.
Let me know what you think

 

That's been floating around recently. Long story short- sorta. I think the conversion requires the use of roller lifters from a different motor becuase they're shorter. You can't drill and tap into an earlier block (86-down) and make it work just like a later 87-up roller block or LT-1 block. The 87-up and LT-1 blocks have little "towers" in the lifter valley that the lifter spider sits on top of and gets screwed into. Earlier blocks have no such towers and so the spider will sit significantly further into the block if you just drill and tap- requiring the different lifters. Plus, what you'd be drilling and tapping into in an earlier block would be just above the main oil galley- which would make me plenty squeemish about doing this by itself.

 

You need to use an aftermarket conversion kit, and they aren't cheap. They use special paired lifters, unique length rocker arms, plus you need a new timing chain & gear set. I haven't seen these kits under $500. I sure as hell wouldn't waste my money on one just to put an LT1 cam in. That cam is so mild that you can do much better with a conventional flat tappet grind for a ton less money. hell, the 85 L98/LB9 cam is almost the same as the LT1 cam, except that I think the LT1 cam has a wider lobe separation angle.