BTW Carb cleaner may leave a film that needs to be removed before you can put a gasket material on. Brake cleaner does not leave such a film.

sweet thanks for all the info!

Derek, i've soaked the studs down with pb many times but they just will not budge. i even cut a small slit in one to try and use a flat head to remove it...nada. looks like i may have to go to the junk yard and buy a lim

You can drill a small hole right through those. You need to centerpunch the remaining stud so the drill won't walk off the bolt, then drill right through. Then a bigger drill, then a bigger drill... when you get closer to the threads stop drilling, heat it all up with fire and put a bolt extractor in the hole, then turn it right out.

Trust me, I've done stuff like this before. That's salvagable!

Make sure you soak them with PB Blaster though. I don't know of any other penetrant as effective.

Sorry, I was typing this while Derek replied, so some of it is redundant.
Have you ever drilled and used an easy out for broken bolts before.?
If not, you have to make a center punch directly in the center of the broken bolt.
I notice the one on the right in the picture is not flat, so you will want to file or grind the surface of the broken bolt flat first, so you can get a good center punch mark in the middle.
Then get a drill and easy out at the hardware store or home depot or wherever you can.
You want to start with a fresh-sharp drill bit.
The bit and easy out will be sized for each other. I don't know what the diameter of those bolts are but you will need to measure that first and get a bit smaller and a new easy out that is sharp. A single bit and easy out will be about $10.00, cheaper than a LIM.
Drill carefully and slowly with a lubricant down the center of the broken bolt, and clean all chips and oil from hole as you go, then tap easy out into hole with a small hammer, use easy out gently to remove broken bolt. You may not get it to move right away but if you keep soaking around the exterior of it with penetrating spray and tapping the easy out into the hole you have drilled with a small hammer and keep trying to turn it counter clockwise it may come loose and thread it out of the hole. DO NOT put so much counter clockwise pressure on the easy out and break it in the whole. Once that happens you can forget about trying to drill out the easy out. It is made of hardened tool steel and almost impossible to drill into it. You can put all the downward pressure you want.
Because it is hardened tool steel they are somewhat brittle and can break under a strong twisting motion.
And as Derek said you can help it come out by heating around the bolts, not the bolts themselves, but the aluminum around them. Aluminum will expand quicker than the steel bolt and allow it to come out of the hole.

The L32 LIM I have here in the garage is cast aluminum.
I don't know if the L67 is the same, sorry for any confusion.

almost certain the lim is cast aluminum. i just washed it down with some wheel cleaner (acid mix) and it bubles like aluminum does. nice and shiny now though
I did notice a area around one of the coolant passages has a rough casting from the factory, should i try and sand it some or not worry about it? need a pic?

Being a gasket surface i would try and smooth the roughest part of that out with a fine sand paper wrapped around a block of wood or something, you want to keep it flat..
Just don't overdo it.
Also, what cleaner did you use.?

Scotch brite pad (green scrubbie).... works wonders.. and some E85 as a cleaner... or 93 if you swing that way

yes it was like they when i pulled it. i am thinking i may hit that area with some black rtv b/c that part of the casting is actally lower than the rest of it so sanding it may make it worse.

Rick, i used a chemical from work that we use on chrome wheels. it is 3% mix of oxylic, hydrochloric and phosphoric acid.
burns skin, clean aluminum and makes chrome look brand new!
it's a comercial product, but i believe napa has something similar in a gallon jug.
works best if you have a pressure washer handy.