If I was doing the project I would find some specs on the 235 Corvette spring installed height and also the spring pressure, then I would check out the specs for valve springs for a 261. The other thing I would be concerned about would be the clearance between the bottom of the valve spring retainer and the top of the valve guide to make sure you have enough clearance.(learned the hard was on a LS-6 years ago) I'm sure Jerry will come along and have more specifics. Don
