Hi guys my name is Jeremy im new to the site here and figured I would give this a try.. I have owned a few mustangs and recently have purchased a 91 Gt. Was told it was a 306 someone dumped some money into it but my problem started with the car smoking like crazy.. compression tested it all cylinders were within a couple pounds of each other . When pulling the plugs #3 cylinder the plug was fouled so I started tearing down and it appears to be the lower intake gasket someone doubled it up and it slid and never sealed.. So now that I have it tore down im trying to figure out what I got. It has domed pistons and at tdc it's sticking out of the cylinder quite a bit . it has world Windsor Sr heads I believe 68cc combustion chamber. was told b303 cam . So how do I go about figuring out compression ratio and how much clearance I have for a bigger cam . I know headgasket thickness plays part in all of this as well.. I have also noticed that the damper pulley is coming apart. and will need replaced can I weigh it to see what I have I know there are two weights and not sure which it is .. block appears to be older as it has the fuel pump block off plate on the side of the block.. haven't crawled under it yet to get the #s off of the block.. any help would be appreciated .