hey im going to install the lb9 heads in 2 weeks ,will they bolt up perfect?some guy told me i have to change the vavle giudes?can u just take of the lo3 heads put a new gasket drop the lb9's put p.r tight up rockers and done?

 

which lb9 heads, 416s or 081s?

 

all i know is that they are from a 87 bird with a 5.0 tpi motor

 

They should bolt up fine. They probably will have the newer style intake bolt pattern since it was introduced that year. Putting new valve guide seals as well as some better springs and retainers from comp cams or another reputible manufacturer would also be advisable since the heads arent in yet. No sense in leaving the stock high milage trash there. Inspect the valves as well. Make sure they arnt damaged or excessivly worn at the seat and/or stems. Other then that you should be good to go.

 

well what u mean the vavle giude seals?im gonna take them to a machine shop for regular clean and new exhaust seals and install some new springs for like a .500 lift and scerw in studs

 

you'll be fine, do that that much machine work, you will need new seals because they will pull the valves for sure.

yes for .500 lift, you need to check valve guid clearnace, if there isn't enough room you will need ot have them machine the guides down. also , you might ask them to use the positive retention type valve seals for you, since you are going to be doing all that work and getting new seals, might as well get the good ones.

 

well u think the vavle guides are to big for .500 lift?and whats wrong with fel pro regular seals?so they should slip right on ?no diffrence right?what pushrods do i use lo3" or lb9?what hp diffrence will i see from this head swap and a single plane edelbrock carb manifold with tbi adapter along with lt1 cam and 1.6 roller rockers?

 

it depends, you need to CHECK the guide to rocker clearance. and machine accordingly, ask the shop to check that for you, they will know what to do.

pushrods are the same IIRC betweent he lo3 and LB9, all the hydrolic rollers should use the same lifters. if you heads or blocked have been decked, then you would need new pushrods. of course it is always a good idea to check the valvetrain geomitry when you do a swap like this, and make sure everything is kewl. but i don't forsee a problem with you using the stock pushrods. just check before you button her up. if your off, get a pushrod lenght checker, and then get a set of custom length pushrods.

HP is going to depend on the tune, and it is going to need it, without tuning, you may not see any HP improvements, its really hard to estimate the HP of a poorly running engine.

 

well but a good hp estimate will be?should i change the exhaust seals or both the intake and exhaust?