Thank you everyone for all the suggestions.. Our son moved to a new house that is up this hill and I drive that road a few times a day as we have been helping him move etc. and my wife has a big garden there as well so I have been test driving the volvo alot since putting in the frost plugs.. We are in a hot dry spell here possibly 37 C today so not sure about carb ice..I had the car parked for 4 years prior to working on the frost plugs but it did run fine before but I never took that hill either.... Everything is the same as it was before I took the intake manifold and exhaust manifold off,, hoses,, distributor etc. although I may not have the throttle linkage just right.. I have thought about the float as well .. On this hill I gear down to 2nd and 3rd to save the brakes as the speed limit in town is 50 kph.. Yesterday I did give it a little some gas coming down the hill and that may have helped.. About a week ago it really acted up and and I stopped and adjusted the linkage and that helped a lot so I obviously had it wrong.. I have tried to find some pictures of the linkage to see the proper adjustment.. One think to add,, I can go up that bloody hill in 4 th gear and the car runs great..The torque of the B20 engine is amazing compared to the B18 I had in my old 1963 122s