If you had an option between '96 DOHC heads that have HLA and a slightly larger intake port and a set of '97-'99 DOHC heads with shim over bucket which would you choose? Would there really be that big of a performance improvement from the '96 head compared to the '97-'99 head? I've done searching but no one ever really addresses the difference between the two and which would be considered a better choice.
Thanks.
Logan
VF43 custom FMIC APEXI intake Invidia 3" TBE JDM Ver. 4 RA STi trans (4.44) SPT short shifter rear LSD WRX rear axels coilover suspension JDM 4-pot front brakes drilled slotted rottors Greddy EBC tuned 20G ECU sti 550cc injectors Jecs MAF walbro 255
The difference is minor. For me, if I was going to leave the heads as-is, then I would look for the '96 set. If I was going to do headwork and/or cams, then the later years are a no brainer as they can be treated as EK20K heads at that point.
If you go back and read the old reviews, the '96 Outbacks/Legacies were considered more 'peaky' then the '97-'99s (albeit in NA form). Depending on driving style, this would likely make them more suited to turbo use w/ the OEM cams.
'93 Winestone SS Auto, '91 Pearl White SS.
'93 Pure White SS EJ20G slanty intercooled, SIDESWIPED! In stasis.
'94 FWD and '95 AWD Laguna Blue SVXs.
2017 Pure Red BRZ Limited w/Performance pack
the 96 dohc heads have a much larger combustion chamber, 53cc vs 46cc of the 97-up. Also, the 2.2 head gasket overhangs into the combustion chamber to the point where i dont think the gasket would seal properly. I have both sets of heads on the shelf and can post pics if anyone is interested in the differences.
94 Supra Turbo 6 speed. build in progress
98 Lexus GS300, single turbo 2JZGTE swap. daily driver
93 Impreza wagon, home brewed n/a-t ken block themed winter drift missle
*sold*
94 Alpine Sport Wagon... STi conversion, rotated turbo etc
interesting, I never thought about the head gasket. Mikey I know you put different cams in yours, which are 97-99 heads. What cams were they and did they simply drop into the heads?
VF43 custom FMIC APEXI intake Invidia 3" TBE JDM Ver. 4 RA STi trans (4.44) SPT short shifter rear LSD WRX rear axels coilover suspension JDM 4-pot front brakes drilled slotted rottors Greddy EBC tuned 20G ECU sti 550cc injectors Jecs MAF walbro 255