heads have to match the intake/cam/engine displacement/driving habit/HP goal/power RPM range/wat the car will be used for/compression ratio... basically everything.
i have the patriot 195cc heads...i just put them on my 383... ive been told that i should be in the 480hp range. with my cam/heads/intake etc i matched my rear gears and converter stall and i should be making peak power like 5500 but i should be able to rev to 6000 with no issues and not losing much if any HP. engine/car specs are in my sig.
larger CC heads like the 225CC vs the 195cc will mean larger intake runners, u will lose low RPM hp/tq with larger heads.and u could make less overall power etc depending on intake and cam that your gona use. basically u need to match everything or your engine will be not as effecient as it should be. larger CC runners will increase RPM range as well as peak HP/Tq numbers... the 225cc heads will be too much for that 383 unless u match the cam/intake for it which will require a LARGE cam and HIGH rpm intake. car will prob rev to like 7000 and will useless on the street since u will need a 4000 rpm stall converter to get into the power band. not to mention little to no vacume at idle for power brakes etc, impossible street idle. u will need really steep rear gears too.. like 4.11 wouldnt be enough. prob like 4.56 etc
compression ratio is all on the combustion chamber size. u can get usually 58-64-72cc chambers on the same heads depending on the company. compression is also determined by Piston compression height/deck height/ piston Dish/dome size, head gasket thickness.
__________________
Formula 383 HSR 9.3:1
SCAT 9000 cast crank, SCAT 4340 forged rods/ARP rod bolts, SRP forged pistons/JE rings, ported HSR, HSR port matched to felpro1206, 58mm TB, grannelli MAF
30lb SVO injectors, patriot 195cc aluminum heads port matched to felpro 1206
XFI280 comp cam, 230/236, .571/.569
1.6 aluminum full roller rockers
handmade aluminum RAM AIR
Headman LTs, true dual 3" with 3" xpipe
700r4, built by me, can handle 700hp, beast sunshell, billet servos, transgo shift kit, yadda yadda
march pullies, smog deleted, AC/heat removed
160 thermostat, 166 on fan switch
8pt CEE roll bar, with swing out door bars, hand made thru floor SFC, Jegster tunnel mount tubular TQ arm, Jegster drive shaft safety loop
UMI LCA relocation brackets, UMI adjustable panhard rod, hand made tubular LCA's,TDS wonderbar, KYB struts and shocks, cut moogs 5664/5665, moog suspension tierods etc
SSBC force 10 front calliper upgrade kit, slotted and drilled rotors, stainless braided lines all over car, rebuilt master, SSBC proportioning valve, rebuilt booster, ford 8.8 11.5" rear disks
FORD 8.8, rear disks, 3.55 gears, rebuilt carbon fiber clutch trac lock(posi) with f150 preload spring, 28spline axles, ARP cap studs and moser aluminum support girdle.
SLP 17x8's fronts wrapped in Nitto 555 ZR rubber
rears will be 17x10.5 ford rims with 315's
NO2 150shot comin soonnnn!!
or dual rear mounted turbos
