SR Blacktop or Redtop?

I am looking at completing a do-it-myself SRSwap but not sure if I should go with the Red Top or Black Top. I am leaning towards a Blacktop since it is not as old.

However, I was told by someone at a shop that the Blacktop is a more complicated swap into an '89 S13. After much research I have not figured out why!

Does anybody know what is more difficult about the Blacktop Swap? What extra things need to be changed?

I have read the list of suggested required and suggested changes from the article on Heavy Throttles web site, Would any body have anything to add to that?

as far as i know the main problem deals with the harness and maintaining airconditioning. IT also has variable valve timing which some people prefer not to have since it creates complications in tuning. Its more preference than anything else

the s14 blacktop has VVT, the s13 blacktop doesnt

the s13 redtop and blacktop are the same engine, just the blacktops are newer… thats it

I would go for the blacktop… cause it’s newer… as you guys said…

Thanks - Thats what I thought but was hearing conflicting answers from engine retailers