what is the difference

i know this is stupid as hell and i know im probably gonna get shit for this but what is the difference between a red top and black top SR20

Black tops are newer, should have less mileage. They have some minor differences like cooling fins on the block, but I believe late model redtops had that to.

so does it matter to buy a black top over a red top and and build it and where do u get a good smooth cover that u can powder coat to replace the red or black top do keep in mind i do plan on doin everything right the first time so i dont want anything cheap i want the best

Wikipedia: SR20DET
VVV
http://en.wikibooks.org/wiki/Nissan_240SX_Performance_Modification/Engine_Swaps/SR20DET

JDM Racing Motors: SR and other options
VVV
http://jdmracingmotors.com/index.php?area=motors&brand=nissan

AF info/updates faqs
VVV
http://www.automotiveforums.com/vbulletin/showthread.php?t=92927

And the later Blacktops have more hp as they came from s14's and s15's. Just read the info/updates one, it tells you everything you need to know.

those sites r kick ass thnx a lot