Does this sound right?
 

Hello new here anyway I am planning on swapping a ls into a 70 camaro I'm restomodding. I found and bought a wrecked 99 camaro z28 for $1700 with what is supposed to be a relatively fresh 6.0 engine that has been dynoed and tuned. The specs the guy gave me are correct as far as I can tell at this point. It is a low mile lq9 bottom end with an unknown at this time texas speed cam (the guy couldn't find the cam card) it has ported 241 heads ( there is porting I went thru the intake with a micro lab scope) btr springs, kooks long tube headers and ls6 intake. The dyno sheet he had showed 421hp and 404flbs torque. Car has a new monster trans 4l60e with a 3400 stall. Do these dyno numbers sound right the shop that did the work can't verify as they shut down about 6 months ago. I'm new to ls engines and just want another opinion on these numbers the guy seemed straight up and so far what he told me has been correct.

Yeah that sounds reasonable but who knows. The thing you need to remember is that dynos vary so need to be taken with a grain of salt. What the car traps doesn't lie. Know what I mean?

Thanks I wasn't sure on those numbers one of my friends who has been in to ls engines for awhile said the 241 heads are junk and couldn't make that kind of power.

Your friend is wrong. The 241 heads can make some nice power when done right

Not long enough....

241's are great heads...AI has a 219cc port program that gets them pretty close to worked 243's. They will make 420whp with a baby cam or 460whp with a big cam.

This is the reason I joined this site I've been getting too much conflicting info from local guys.