What CC are GT40's chambers.

[T_5.0_N'works]

Hey I recently bought some GT40's that were from a marine application from some one claiming they were 64cc heads. I kinda thought the 64cc was stock chamber size but I looked at the chamber and it doesn't look like theres a lot of room to equal 64cc. Might be 58cc. Anyway you can check by eye balling it or while the heads are off the car? Will porting them open up the chamber enough to make a difference? I'll post a pic later today of them.

 

[T_5.0_N'works]

Did I do something wrong, not enough info? Please help.

 

[Stangfreak95]

On Summit's website, you can find some GT-40Y and GT-40X. BOTH are 64CC's I dont know if there is other sizes. Call a good performance shop. You'll have an answer in seconds.

 

[90lxcoupe]

if you look in the mustang unlimited catalog they sell gt40 x heads with both 64cc and 58cc combustion chambers.

 

[T_5.0_N'works]

Ok, worst case scenerio they are 58cc, won't tell until I put them on the flow bench. Would porting open them up any? I would like to run a boosted motor so 58cc kinda on the tight side, I need more like 62-64cc. Possible with some porting?

 

[PURESTREET5006]

Are these the iron GT40 heads.If they came off of a 93-95 cobra then the chamber size is 62cc but if there from FMS OR FRP then there 65.5 cc's i'll get the casting numbers so you can tell the difference.

 

[T_5.0_N'works]

I was told these heads came off a 351w MARINE APPLICATION, so it was probably and inboard motor on a boat. Very low usuage hours, was totaled in flood and sold engine, been rebuilt and now I have it.

My casting #'s are F3ZE-AA

My original question was how can I tell teh CC chamber, NOW. It looks like he took some metal off to get a small CC area. Is there anyway to eye ball them?