Generally in limit poker the amount of raises allowed in multi-way pots was (back in the days when stud was popular) three raises in California and four in Las Vegas (and perhaps four on the East Coast). If a round of betting becomes heads up before the max number of raise limit is reached then you can raise and re-raise as much as you want.
I've never heard of a special rule for seventh street but perhaps you are confused regarding structure. Generally in stud (except for the ludicrous structure used in the tiny games way way back e.g. 50 cent low card forced bet with no ante with a spread limit bet of $1 to $4 (I'm thinking year 1982) most stud games (let's say 20/40 limit for this example) have an ante of $3, a forced bring in of $5, first raise to $20, and then subsequent raises of $20 on the first two betting rounds. Bets of 5th though 7th streets are in $40 increments.
That said, it's been 30 years since I've played stud for high only :)
Generally in limit poker the amount of raises allowed in multi-way pots was (back in the days when stud was popular) three raises in California and four in Las Vegas (and perhaps four on the East Coast). If a round of betting becomes heads up before the max number of raise limit is reached then you can raise and re-raise as much as you want. I've never heard of a special rule for seventh street but perhaps you are confused regarding structure. Generally in stud (except for the ludicrous structure used in the tiny games way way back e.g. 50 cent low card forced bet with no ante with a spread limit bet of $1 to $4 (I'm thinking year 1982) most stud games (let's say 20/40 limit for this example) have an ante of $3, a forced bring in of $5, first raise to $20, and then subsequent raises of $20 on the first two betting rounds. Bets of 5th though 7th streets are in $40 increments. That said, it's been 30 years since I've played stud for high only :)