New autometer temp gauge and sending unit is exactly what the infrared is reading at the sending unit. Makes me think its right. After I pass the 230 mark there is enough pressure to push out to the overflow.

Ok. Check the pump, gasket and dividerplate as suggested earlier. I would also check for exhaust fumes in the coolant. A good repairshop should have the equipment to check the exhaust gases, in this case you should use it on the coolant (not directly in the liquid though). Do you have the springs in the radiator-hoses to prevent them from collapsing?

Still need to know a 100% about the divider plate as to whether or not the 68 requires 2 gaskets or one. If it is 2 I have the wrong dividers as the ones I have fit inside The timing cover And not in between 2 gaskets. Just trying to double check every part and possible problem.

You have water that is 230 degrees in the block and water that is 130 in the radiator, you have a flow problem. Either there is a physical obstruction in the block preventing the water from leaving or the pump is inadequate to move the water out of the radiator into the block.

Those are my exact thoughts. I would pull the thermostat and check the flow with a garden hose. ( with the car off)

That's what I have been kind of thinking but I see it circulating thru the radiator. Just may not be enough. I don't know what to do if it is slow flow as I stated before its a fresh build and the block was tanked and cleaned at the machine shop. I will try to check the flow more closely and try to figure out if it is enough.

Just by looking at the radiator through the cap opening is not going to be enough to determine flow. I have been trying to think of a way to test flow but cannot think of one. Go back and look at post #17, the pump, the impeller, and the divider plate all have to be correct in order for the pump to pull enough vacuum to ensure correct flow.

Will be pulling the pump again tomorrow to recheck all of it. Just wish I could get a 100% confirmation on the divider plates. The ones I have with my 8 bolt water fit inside the timing cover housing and only 1 gasket is used. If this is wrong it could be part of my problem.

When you pull the pump please take some pictures. I would like to see what the pump looks like.

I would also like to see what the fan looks like. I have a pretty big fan and I would like to see yours and the shroud.

I also found this the other day. Looks cool and is a great diagnosis tool. I would get the Chevy one as the Pontiac one looks too big for no good reason..

http://www.coolviewthermostat.com/

Dave

I will take some pics to post tomorrow that may be a big help.

After a long talk with Jim Butler from Butler Performance yesterday I decided to wait before pulling everything a part again and recheck the basics. Great bunch to deal with if you haven't already. After our discussion we determined my timing wasn't set correctly (needed set with vacuum hooked up). Done this morning only to discover that at 2500-3000 rpms I am getting about 45 degrees of total timing (not good). Got to get that fixed before going any further.

Also there was mention of a possible issue if I used felpro head gaskets (which I did) concerning the water jacket holes in the gasket. The water jacket is a 3/8 and the gasket is 3/4 which gets it real close to the compression ring in some cases. I hope that's not my problem.

I blew both head gaskets when I put mine together about 10 months ago because of the problem with the felpro head gaskets. All it did was a small hic-up & blew the head gaskets. I to talked to Jim about this problem. The best thing to do is replace the head gaskets with the ones Jim says to & be done with it. His gaskets don't have that problem . It sounds like you blew your head gasket(s) as I did. Your problem sounds just like what i went through until I to talked to Jim about the problem. Change them & be done with it. You'll be much happier in the long run by doing it. Then your problem will be gone & you can drive the car without worry.

I really, really hope that's not what it is but if so Jim will be the first person I talk to and the gaskets will be ordered. I hope the timing is the problem (fingers crossed).

Ok I unhooked the vacuum on the distributor and reset the timing to 16 initial. Reset the carb mix and idle Drove it down the road a few miles and it ran great and never got over 190. Even though it was in the lower 60's this morning I think I may have got most of the problem under control. Big thanks to everyone for your help and also to Jim Butler for giving me a call back.

And to calm your fears about the water pump, on the 8 bolt design like yours (68 model), there is only one gasket. The divider plate indeed sits inside of the timing cover, and doesn't require a second gasket OR the sleeves that the later (69 and up) 11 bolt designs do with 2 gaskets.

Glad to hear you're getting it fixed!

:)

Great thanks.

Attachment 297908 Maybe I will finally get to see this blue outside instead of just in the garage.

I don't think your going to be any happier after you rset your timming. If it were an issue of timming all the coolant in your system would be hot at the same time. I went through the same things hoping it wasn't that but in the long run it was the head gaskets. Just look at it this way the longer you wait the longer you don't get to drive the car. Just break down & break in down tear it down & replace the head gaskets now to save a little of that OH so prrious time & replace them. If it were timming the coolant would heat up as it was circulating & it would all be hot not just in the engine until it gets so hot it bloes the raditor cap seal into the overflow. I know you want the best news, & I have to ask have you taken the t-stat out & run it without it in the engine & watched the coolant to see if it is circulating & if so was there bubbles in the coolant while it was going around??? If you have bubbles you have a blown head gasket(s).

Well after pulling the vacuum and resetting the timing then taking on a 6-7 mile spirited drive it never got above 190 . I have pulled the t-stat prior to this and the water is flowing thru without bubbles so I am still hoping its not the new head gasket and was just way to much timing.