jason

What should engine temp get to be on 68 cutlass with a stock 350? Ours got to about 220 today. Not a real hot day out. But furthest car has been driven since motor rebuilt. Otherwise ran great. Think t-stat is 195.
Also did these cars have a regular fan shroud or fan clutch?

Fun71

With a 195 t-stat the engine should run around 195-200º.
Fan shroud and fan clutch depends upon the car's options. AC and HD cooling had them, but no AC, no HD cooling didn't.

As for your 220º temp, was that at idle, slow speed driving, or at highway speeds? There are lots of things that can cause an engine to run hot, so we would need to know details in order to help troubleshoot.

76olds

Kenneth really covered everything needed to give you some advice, I think we would also like to know what rad your currently running, factory style 2 row or 3 row HD copper rad. Has it been re cored or replaced previously. You may want to pull it out and flow test it. Would hate to hear that it boiled over on a hot day and took out a head gasket or worse. Just a thought hope this helps.
Eric

Octania

Retarded timing can lead to overheating...

Yellowstatue

All '68's had a fan shroud, even the sixes.

brown7373

You say the engine is a new rebuild, but was the radiator also "rebuilt"? Sediment and corrosion tend to settle in the bottom of the radiator, restricting or closing the bottom tubes. A back flush might get out the loose stuff, but not the serious gunk. A few clogged rows of tubes can decrease cooling by 10, 20 30% and still flow normally on the top 3/4. A les that 100% radiator with a fresh, tight rebuild could easily run hotter.

Octania

Not your W30 MT cars...

so sayeth the assembly manual, and the man here in Lansing who used to assemble them.

Yellowstatue

A friend had one (W30, four speed, NEW), and I didn't notice if it had a shroud. If only I could go back in time and peek under his hood again.