1sc334

So you are advising the smaller cubes even for a DD pump gas motor and how would Stock crank work if i upgraded to the YSI or did u just mean stock Stroke ....and at wat RWHP level would u say i would Need the iron block or do u prefer it over the STOCK LS BLOCK ??? I know its alot but everyone i talk to gives different advise....

1sc334

Wat did you guys pull motor to and are you saying you have the 243 heads on a 427 n if so wat were ur torque numbers??
And how many pounds of boost?? Fuel? N ect....

aTX427

I was wrong. It made 900rwhp on my 427 with 243 heads. Looks like 18.5# of of boost, but that number is somewhat irrelevant, because boost is a factor of head efficiency. I also attached a comparison I did a long time ago showing the 243 head / F1C build to my ETP LS7 / FiR build to an LS7 with a YSi. I cannot recall who's car it was though, but you should get a feel for what the different heads produce. I came across a good deal on a set of ETP LS7 heads with Jesel J2K's, otherwise I was going to buy a set of TEA TFS 245's. In all honesty, I should have kept the 243 setup, because making the jump to 1,000 rwhp cost me another $10K.

Silver Bullet C6

I went with LSA heads also on my ERL 427/ YSI build by Josh from A&A (when he was in Texas). Arun did the cam.

Jeffro_510

I was really close to going LSA heads on my car, ended up being cheaper to buy my AFR's.
Converting to an LS3 style head also requires different: injectors, fuel rails and intake manifold.