I have a older home with Alum. Wiring. I'm want to hook-up a new 220 cook top. My service line is 3 line, two insulated and one bare strand ground. The cook top has 4 wires Blk,Red,Wht, & Grn. Do I connect the Red and Blk (hot) one each to the two lines fron the servive panel and then connect the Wht & Grn to the ground?

If this is a new range, your owners manual should tell you. Basically you relocate the chassis ground. Look in your manual. PS It is now 240VAC.

Owners manual does not show anything about relocating the chassis ground.
I have two insulated alum. Lines and one ground line from the service box. (220)
The new cook top has four wires, Red, Blk,Wht & Grn. How is this connection made?

When you say "service line", I believe you are speaking of the power cable from your power company to your main service panelboard.

If the branch circuit is an existing 3 wire receptacle or hardwire connection then it comes down to the manufacturer's electrical instructions.

If the instructions allow for the 4 to 3 wire connection they will state that.

If the instructions do not say that such a conversion is allowed, then you must have the proper sized 4 conductor cable pulled from the main electrical panelboard to the cooktop location.