TT Legacy heads on Forester?

[stiwagon]

Hey guys,

Ive got a mate with a 1999 Forester Turbo that has damaged valves.

My question is will the heads off a \'98 twin turbo legacy bolt straight on? We would use the heads, valves etc from the twin turbo and then re-use the cams from the forrester. I have been told previously that twin turbo legacy heads are the best flowing for WRX engines so I\'m guessing it should work but want to know for sure.

[Koom]

Possibly will run into an issue with the bolt pattern for the intake manifold as that\'s around the change over period between phase 1 and phase 2 for the ej20. The 98 gtb heads will have the bolts in a straight line and if the 99 engine is phase 2 the bolts will be offset.

If that\'s not an issue and the manifold fits, why not use the cams from the gtb? Not sure if the cams are interchangeable between solid lifter heads and hydraulic lifter heads anyway? May not be an option as you\'ll most likely have to stay with the solid lifters in those heads and do you really want to be re shimming all the valves?

[Rosssub]

If it\'s a 98 BH EJ208 they will bolt straight in. Post 6/98

If it\'s a 98 BG EJ20K See Boon\'s issue above. Pre 5/98

Cams wont be interchangeable.

Either way I\'d be measuring Dish sizes/Depth and comparing both heads. You could end up with major Pinging/DET/Knock CEL/Limp Mode/WG Spring Pressure if the C/R is too far off.

I think both Cars run different Compression Ratio\'s OEM, but neither have Forged Pistons. So the main Compression difference could be in the Heads Dish?

Edit: Either Dish or HG Thickness, 0.8 crushed to 0.7 on the BH TT. Then maybe 1.6 crushed to 1.5 on the Forester?