Hi, I'm about to put a ls6 243 heads and futral 224/224/588/588,114 cam,ls6 intake with ported tb,lid with filter,slp cold kit,edelbrock shorty headers,catback borla exhaust,slp y-pipe,36lb injectors,walbro pump and all smog components attached. I was wondering how much rear horse power can i get out of these mods with a basic tune? Also what type of spark plugs goes good with these setup and what gap setting should i do on the plugs?

 

390-400 rwhp would be my guess with an M6, 350-360 on an A4 locked. You'll want to run NGK TR55's most likely, or an iridium.

 

my guess is 405 or so considering with just that cam and supporting mods you can get 380 to 385 realistically...take it to the track though and see what happens! seems like your goal is 400rwhp and still being able to pass emissions and have a good torque curve moreso than peak power...if thats the case, you will succeed, but lose the shorties and get longtubes