Shouldn't be any big deal to swap out cam and lifters for hydraulics. Why don't you call one of the major cam makers (your favorite brand) and run it by them. They should be able to suggest a good grind and guide you on any other changes you need to make, such as different length pushrods.

I love these big Olds engines. We built a similar one for my Kids '29 (forged flattops, good heads, Crane cam that verges on radical, and a tripower setup from a '66 W30 Olds 442. We backed it with a built 350 turbo, and 2800 stall convertor. It should move the little roadster pickup pretty well.

We had a slightly milder version in my other Sons JetStar 88 convertible, and I borrowed it one day. When I kicked open the trips coming out of a toll booth it nearly scared me to death. These things are torgue monsters.

Don