Everytime i talk with this person we get in an arguement. He says there is 2 different kinds of S13 Redtops a zenki and a chuki.
I said there is 1 kind of S13 redtop from 91-93 and that there is a S13/S14/S15 blacktop as well. And that CA18DET’s came in the zenki 89-90 S13 and that SR20DET’s came in the 91-94 chuki S13’s
Who would be right?
There is 2 types. I dont think inside there is any differences but you can see the castings in the cyl head are different. 1991 has a smooth cast and 92+ has a bunch of lines going up and down on the front of the head. This is how you tell if you had one of the first SR’s 
So ya I guess he is sorta right but who cares, SR red top is SR:P
Finned Red-tops are more likely to have blacktop internals. The blacktop internals are slightly stronger and can be reconized from their casting number (54C) on the under side of the piston.
I know cuz mine does :E
There is a S13 redtop, as well as an S14 one… You can tell the difference from the cooling fins on the front of the head… also, the S14 ones will have VCT and the ball bearing t28 turbo.
Actually there is no s14 redtop. The s14’s all got blacktops. Although redtops were still made at the same time for the 180’s.
Redtop’s where only made untill early 93. Then they switched over to a normal blacktop(NO SLANTED VALVE COVER), and later switched over to the Type-X motor in 96-97. These were only in S13’s and the 180SX’s that were produced in Japan untill about 98.
S14’s never had a redtop, They all came with VTC and had a slant in the back of the valve cover. They were the exact same for all S14’s
S15’s had a slightly upgraded version of the S14 motor with bigger injectors and the STD. cars got a slightly upgraded turbo. The automatics had the same turbo as the S14
Hopefully this gets rid of the confusion.
There Never was a redtop in a S14, And when S14’S were being produced there never was a redtop in an S13.
NICO had a good list of the differences and the Exact dates
Wow good info that clears up even my confusion.
see what happens when u think you know what your talkin about man get your facts straight before you open your cake eater acting like you know everything about nissans.
ohh yahh and its kouki you nissan specialist
If your talking about the s13 comment at the top, chuki is correct (91-94). Kouki is s14.