126 Thermostat Housing question
 

Just replaced my thermostat with a new gasket but now I have developed a leak...seems to be coming from the bolts that hold the thermostat housing to the block (I replaced the old bolts with M6 Bolts x 30 mm -- they are slightly longer and protruding). Are the longer protruding bolts the cause for the leak, or was there supposed to be another paper gasket in between the housing and the block. (I, of course have the rubber gasket on the thermostat).

Thanks for the replies in advance.

If the bolts are longer you may not be snugging down the housing enough. Get the correct bolts.