shovel
Active Member
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- Jan 4, 2023
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I'm about to get started on springtime upgrade/maintenance on my 94GT and have a set of X heads (F3ZM 6049 X302) which I believe have 64cc chambers.
I have a stock 5.0HO cam and both 1.6 (SVO) and 1.73 (Scorpion Endurance) rockers to choose from.
For reference these are the numbers the internet claims

Questions:
* Going from 61.5cc to 64cc on a stock 9:1 compression ratio means I'd be like 8.8:1 or so - is that going to offset the improved aspiration? I'm staying naturally aspirated on this engine.
* As I understand it the stock cam for a 94 GT is 276/266 duration; .278" lift; 116 lobe center int/115 lobe center exhaust. So that means .444 valve lift with 1.6 rockers and .48 lift with 1.73 rockers. Any reason to go one vs the other?
I have a stock 5.0HO cam and both 1.6 (SVO) and 1.73 (Scorpion Endurance) rockers to choose from.
For reference these are the numbers the internet claims

Questions:
* Going from 61.5cc to 64cc on a stock 9:1 compression ratio means I'd be like 8.8:1 or so - is that going to offset the improved aspiration? I'm staying naturally aspirated on this engine.
* As I understand it the stock cam for a 94 GT is 276/266 duration; .278" lift; 116 lobe center int/115 lobe center exhaust. So that means .444 valve lift with 1.6 rockers and .48 lift with 1.73 rockers. Any reason to go one vs the other?