My old 1984 C4 Corvette is in need of new valve guides. The car has the crossfire system that works perfectly and I am not interested in performance upgrades as the car is used in the summer to go to various out of state car shows and gets terrific 26 MPG on the highway and besides I have a 79 Corvette that I build for street / strip racing that takes care of my speed fix. The question I have that no one can seem to answer is the availability of a aluminum head that would be compatible with the stock manifold ? I do plan to port the intake as that should have been done by GM in the 1st place and will also be installing new throttle body bushings. So does anyone have any suggestions ? or should I just have the original heads rebuild ?  

valve guides??? the valve seals on that motor are replaceable...  and are not the O ring type... they are down around the guide and have a retaining ring holding them in place.(hose clamp sort of)..  they can be changed with a 15 buck tool , and some care...

there are some carb shops that will rebush the throttle bodys and do a fine job... the throttle blade screws are tiny and metric and the end has to be ground off before you try to do anything else but loosen it to ajust the centering...

i have rebushed them using 3/8" thin wall valve guides i got from an engine rebuilder...

letter Y drill.. .404"
thin wall vg.. .015+.015 wall thickness
shaft diameter .372...
work the shaft in  in with lube...

k-line make a tool kit to do this... but if you are handy you can just drill it..

screws are like 2.5mm.060 pitch as i recall


and for longer life.. you might want to install new valves with oversize stems instead of valve guides...  you might also spring for  hard seats just to be on the safe side.. the hardness is just on the surface...

and for aluminum heads... i wonder if there are any of the gm 350 vette aluminum heads left that were so popular a few years(decades ago)  

Thank you so much for the information your provided, I will be pulling the heads and send them out to have new valves with oversized stewms per your recommendation. One small problem is I can not find any shop in my area "Washington DC" that can install the bushings do you know of any places that I could send too ?  

On the head question, the Cross Fire engines use the standard Gen I small block intake bolt pattern, so any good aluminum head will work. If you're on a budget, I'd suggest a set of Corvette L98 aluminum heads, but if you've got the money look at a set of new heads from RHS or Edelbrock.

On the valve seals, your engine has both the umbrella seals that cover the guide, and the o-ring at the top of the valve stem. The guides being worn out depends more on how much mileage you've got on the motor, opposed to the valve seals which relate more to the age of the motor. To help make changing the seals easier, Crane has a great valvespring compressor that is the best out there for motors like yours. Part number is 99473-1

Since you'll have to pull the springs to change the seals, I'd recommend changing the springs while you're there. The factory valvesprings are notoriously weak. I'd recommend either a Cran 96802 spring or a Comp 941 spring.