I need to replace my radiator cap not sure how many ib cap it was
I have a 440 with 180 thermostat and alum radiator with small over flow. is a 16lb cap about right.

16lb is what the factory 440 radiator called for on my 70

what would happen if I went with a higher pound cap I have a 22lb cap that came with my radiator it was made from HOWE

It will just retain more pressure which could cause a higher boilover temp point. I dont think it will hurt did the car run warm before?

The 22 lb is more of a racing app so it'll withstand a higher temp b 4 it boils and pukes. You'll prob not get near those temps; boiling point 212 deg F (pure water at sea level) & I think antifreeze lowers it a bit but not sure + the cap raises it 22 times ~3 deg b 4 it opens and if you have/want a recovery cap/bottle you want a lower (the std 16lb) cap so it'll purge the air out which lowers temps slightly (elims air pockets)/inhibits rust (less air (oxygen) in the system) otherwise either a 16 or the 22 will work fine, just keep your temps in the normal range EDIT actually I think antifr raises it a bit

Rapid I wanna say it brings it with antifreeze to like 260 with a 22 lb cap but im very forgetful

The last "safety valve" for temp control is boiling. When the coolant boils it removes a lot of heat and lets you know its about time to pull over. The 22 lb cap will boil at higher temp... enough higher to hurt the engine? I'd prefer to keep the "safety valve" set a little lower with the 16 lb cap.

I estly dont think the 22 will hurt if the car doesnt get hot anyway but sometimes its better to be safe then sorry. I wouldnt run anything less then a 16 though