is now available for retrofit on l-98 tpi engines and other street/strip ... utilizing standard or gm vortec chevy cylinder heads the manifold is designed ... for gm vortec and standard small block chevy heads · fully cnc machined for a ... 10.25 · for tpi conversions use earl s 9894dbherl 14mm x 1.5 thread or 9894dbjerl · ... satin polished 7540p 1957-86 262-400 sb chevy v8 7540 1987-later w alum heads 1987- ...