zo.six

I'm getting ready to order my heads but I am having a hard time choosing heads.I like the Mast 305 LS7 heads. I also have been looking at mast 285cc ls7 . Help me choose!

THE HEADS FOR LSX 427 cid BOOST ENGINE
F1R PROCHARGER WITH DALLAS PERFORMANCE COG DRIVE 20psi

TRINIC5

Just my thoughts, since you're running a F1R Procharger and you still have the choice to chose a set of heads , the best will be the bigger flowing heads which would be the 305.
Forced Induction like the biggest and best flowing heads, so get the 305.

ZO6er

I have the 285's, they're great. I would've gone 305. To me it would depend on your valve train and cam setup. GL

0Arun@CCP

Make sure you get the lightest valve possible!

0Taylor@DallasPerformance

Either head will work well. The 305cc heads have been our choice on this combo, especially with our F1R/LS7 blower cam

zo.six

thank you for the replies

BADZ

My next mod will be the 305 heads/new cam/intake.

flyinmedic

I have the 305's and they worked very well

GAMEOVR

What's the cfm flow on these heads does anyone know? I assume you can't go wrong with Inconels in there as well that's what I did.

Either way nice choice with the heads should work very well for you!!

Bad News

What are the 305's going for with titanium intake and ss exhaust valves?

hemorrhage22

I realize this is an old thread, but i'm really interested in knowing what head would be best for the mentioned application

I have an F1R procharged 427 LSX with 40 teeth pulley which should be making around 22-23psi of boost with and Mast black label 305 heads. I am currently making around 930 whp.

I've been told by so many people that going with the smaller heads would generate more power but this just doesn't make any sense to me. On MAST's official website there are tables for flow data, when comparing the 285 with the 305 you notice that they both have the same exact flow rates!

The only difference between the two heads is the intake port volume.

The question remains, WILL I BE MAKING MORE POWER IF I SWITCH TO A SMALLER HEAD? IF SO, WHY?

Unreal

I doubt it would change. You are only going to make the power your blower is putting out. Want more power, turn the blower faster.

ProEFI

I used the 285 and now building a new engine with 305, if you're not going to increase your bore then 285 is enough for 427CID IMO but if there is 1% chance to go more then go a head for the 305. best of luck and hope to see numbers soon.