So i have a lstec build i put together using a new headgasket arp studs and a freshly machined b17 head that i bought converted for ls v, and a stock b18a1 block. I am having problems with it stuttering at 1500 rpms. also there is no pressure building in the upper radiator hose. And after running it for about ten minnutes i checked the oil and there was coolant in there.. its not blowing off any white smoke. is there something internal where coolant is getting in there? i have checked all the coolant lines coming off the thermostat housing and they all seem to be in place. i have the heater deleted. the head has a plug on it where the heater return line issupposed to go and i blocked off the line that comes off the t housing. im really hoping this is not a blown hg. please help.

 

Simple, do a compression test or leak down test if you can.
Pressure testing the cooling system would help as well.

Believe you can rent these tools from most autoparts stores if you don't have access to them.

Otherwise, take the radiator cap off and start the car, if coolant bubbles out of the radiator neck, you most likely have need to do a head gasket.