[helmerrock]

I am in the process of preparing a set of 061 heads. I’ve had the guides cut for PC seals and have new valves stock length single groove. I’m finding that the stock retainers are about.050 too long on the bottom end and with run into the seals. Valve lift is under .470. I’m not sure what is the best solution. 1. Could I machine .050 from the bottom end of the stock retainers since the extra length is not needed for “O” ring seals. 2. Are there aftermarket retainers that are shorter than the original stock ones? 3. Could I use .050 offset locks and shim valves to gain clearance? 4. Go back to machine shop and mill tops of guides? Any guidance or advice is appreciated