Zed'er

I have to wait till spring to get my Trickflows, so I am taking in a pair of 416's to get some machine work done. I have a valve machine & seat grinder, so I'll most likely get around to putting in 1.94's before any machinework done (also, some home P&P). They will be tanked, mag'd, resurfaced, machined & tapped for screw in studs w/ guide plates, and have the valve guide bosses machined for positive seals.

My question is, Will having the guide bosses machined for the locking valve seals increase the amount of lift that will be available over stock, or would it require even more machining? I'll be looking to stay under .500" for lift.

leeperryracing

should be good to about .480" lift depending on the valve springs.

86camaro383

iTrader: (3)

Agreed. You dont really wanna go above a .480 with a stock converter (assuming its auto) You can go really to any lift, as long as your springs match the cam and are installed at the right height.

leeperryracing

remember, if the heads can't flow to match the lift, thats also pointless

Damon

If the head already had factory-installed positive seals on the valve guides (don't know if 416s did or not) then you'll have about .470 clearance with the seal installed.

However, if those heads never used positive seals on the guides and you install them you can lose significant clearance with a seal installed on an unmachined guide. If you've got them apart you might as well check. If you need to machine the guides down (or smaller in diameter) to fit a positive seal then this is certainly the time to do so.

Sonix

iTrader: (1)

My 416's had non-positive seals stock.

This is exactly what you want to do. Use the cutter to machine it thinner, and at the same time it cuts the top down. Bring it down .050" or so, that should be enough.
Home ported 416's will like in the high .4xx" range lift, thats for sure.

Zed'er

I am having them done, that's why I asked. The springs will be matched to the cam, and I'm looking at nothing bigger than a 214/224 and I'll have about 448/471 at the valve with my 1.52 magnum roller tips. I though a stock 416 could already handle .480" of lift.

Sonix

iTrader: (1)

if you're putting on trickflows later, are you also replacing your cam again?
I'd put in a respectable cam now, so you don't have to re-do it later.

3.73 and the T5 eliminates the hassle of torque convertor and whatnot.

My 416's didn't have the valve guides machined, and I had .535" lift on the exhaust, without problems. Reason being is the aftermarket retainers, which may have been offset ones. (or the locks being offset, I should say). My machinist assembled my heads for me.

Zed'er

Yeah, I will actually be going to a larger mechanical cam with the Trickflows. I don't mind doing it later, besides, I don't really want to grenade the T5. I am rebuilding a TH400 for the beast, for later use. I have another 010 block that I may put the trickflows on (just pulled and disassembled last night). It was recently rebuilt with a fresh .030 overbore, but sometimes I don't trust other peoples work, especially when it had mismatched heads on it (which prompted the teardown, lol).