here this is the issue i am having i am building a car for dependability but at the same time be able to drag race it all day and not break like alot of people at the drag strip that i have seen. what i want to know is which one is more dependable aluminum or cast iron cylinder heads. i have heard the aluminum flows better and it is easier to weld and so on but i have a pair of cast iron gt40 heads and and a pair of aluminum gt40 heads what i want to know is which one is more likely to break thank you for your time. makrf-250
I answered this before, but the post seems to have been lost. Go with cast Iron. Aluminum tends to warp, crack and is not compatable with some anti-freeze. If you port and polish the heads, you will not have a flow problem.
Aluminum vs cast iron to me my question is - what are you bolting them onto? If your block is iron then I think the cast iron and if the block is aluminum then go for the aluminum heads . To me" like" metals react better together than different . Also for a drag car your engine "life" ticks away with every run , you better have more than 1 engine and LOTS of parts ! Good luck! Safe racing !