I need help deciding on the best patriot heads for my set up. Mods are in my sig. Heres the two heads im looking and the specs.

2013

Combustion Chamber: 64cc
Intake Runner: 227cc
Exhaust Runner: 70cc
Intake Valve: 2.02"
Exhaust Valve: 1.57"
Max. Valve Spring Lift: 0.650"
Spring Pressure Closed: 135 lbs. @ 1.800"
Spring Pressure Open: 375 lbs. @ 1.090"
Retainer Material: Titanium
Valve Seal Material: Viton
Valve Guide Material: Manganese Bronze
Valve Job: 5-angle

2015

Combustion Chamber: 64cc
Intake Runner: 227cc
Exhaust Runner: 70cc
Intake Valve: 2.08"
Exhaust Valve: 1.60"
Max. Valve Spring Lift: 0.650"
Spring Pressure Closed: 135 lbs. @ 1.800"
Spring Pressure Open: 375 lbs. @ 1.090"
Retainer Material: Titanium
Valve Seal Material: Viton
Valve Guide Material: Manganese Bronze
Valve Job: 5-angle

The main difference i see is the intake and exhaust valves. My concern is the intake and exhaust runner size. They are both the same but i want to make sure there not to big for my application.

 

Come on guys

 

the 2013 is for ls1 3.9 bore,the 2015 is for a ls2 4 bore.

 

I read that but becuase there the same runner size 227 intake and 70 exhaust the only difference being the 2015 has different valves and better flow numbers is that head going to hurt performance for my LS1 or better it?

 

you want the 2013 for a ls1,the valves in the 2015 are too big for a ls1 bore.

 

Well does anyone have feed back on the 2013 heads? Like them? and power with them?

 

do a search in the dyno section,or consider some TSP ls6 heads stage 1 or 2.5.