DM91RS

Glad to see the site back and with a new mod! I am building a 350 TBI with an L31 shortblock, vortech heads, LT4 cam, 1.6 rollers, edel vortech intake, and holley 670 with 65lb. injectors. When I checked retainer to seal clearance I only had .460. Needing .480 plus I was going to machine the guides lower and install new seals (postive type as came on the heads). I think that I read a previous post in which Pablo mentioned umbrella type seals and was wondering if they would work and keep me from having to machine the guides and how well they seal?

Pablo

iTrader: (1)

im pretty sure the seals on those heads are umbrella seals allready or some variation of them i think all late models like after 88 or something came with them. I didnt have a problem with my heads so i dont know what the course of action is in your situation i guess machining down where the seal goes or getting shorter spring retainers

FastBroker

Yeah, you gotta get the seal lands machined to afford at least .040 of clearance under full spring compression, at least that's what most builder recommend... Call your local (reputable) machine shop and ask them.