FASTONE

What size ports do 5.3 heads have and will they flow the same as LS1 5.7 heads,also what is the biggest valves that can be put in them and how much can you mill them and what CC chambers will they have? I,m putting them on a410 stroker built just for 1/8 and 1/4 racing.Also what size solid roller cam do you think I coulduse?I want to run .650 to.700 lift with say 250 to 260 duration @.50 as I want power from 4500 -8000 RPM.Cam would would be 108 or 110 LDA.I want to run 1.9 Jesel shaft rockers.This is going in a 81 Z-28 with an automatic tranny 5000 stall with 4.88 gears car will weight around 2300 pounds.Also I am going to build a sheetmetal intake to run 2 carbs,probably 2 750 demons.May also run some NO2 later.Does anyone make domed pistons say 0 cc,s with valve relieves for 4.04 bore and 4.00 stroke?Any ideas and or advice will be appreciated!!!!

FASTONE

ttt..

Mike Frey

Well, I can answer part of your questions. They are basically the same as LS1 heads as far as ports go (200cc int./70cc exh.), with smaller (61.15cc) chamber and a smaller intake valve (1.89 vs 2.00in). According to "LS1/LS6 Performance," the can be milled .030 in. I dont know what chamber volume that would give, but the book says 11.5 CR with a 5.7L. They should take the same size valves a LS1 heads, but maybe less with the smaller chambers. The only advantage seems to be the smaller chambers. Unless you are getting a great deal on them, I would go with the new PP race heads from Texas speed. 2.08/1.60 Valves, ported LS6 design, hand finished, and several chamber volumes available. See this thread https://ls1tech.com/forums/showthrea...7&page=3&pp=30

Hope this helps.