Slot port on alpine type r's

Im working on a friend's car, he just bought two alpine 12" type r's off of another friend of mine.  He wanted to port them but he doesnt have a ton of room and honestly neither me or him are capable of buildng a port to size like that.  We have talked a little about slot porting it, these two 12s will go in the back of a 1997 honda prelude.  Anybody know what a good frequency and port dimensions would be for these subs?  He's looking for them to hit hard but obviously doesnt want to sacrifice too much SQ, any help would be appreciated as I have never built a box like this before and dont know all that much about slot porting, thanks.

check ur alpine manual dude. it should have layouts for a few boxes, in not sure tho. also check alpine.com

Whats he powering them with?2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.

Hes powering them with a fosgate p6002, and I checked the alpine owners manual online and it didnt really give a recommended port size, so alpine guy if you have some experience here please help me out, thanks.

i pay people to port box's haha.   So usually i ask for around 35-40 hz .   Iv never had time to experiment with porting yet, so i can't help too much.2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.

Haha honestly I would normally do the same, Im a little scared about porting this box but its always fun to experiment.  Is there many an alpine tech support line that I could call and ask about port specs and sizes?  Any help I can get on this would be great guys