Product Description Specifications Precision machined from 6AL4V titanium, these retainers feature better material consistency and bullet proof durability. These 10 degree retainers fit engines with 1.250" OD valve spring such as our 980, 981 and 941 springs. Category: Engine Components>Valve Springs, Retainers Core: N LTL: N MPN: 728-16 Proposition 65: Y Special Order: Y