If you are talking about the "head bolts" they are 19mm (3/4" AF) six sided, you don't want to be tightening head bolts as they a torqued to yeild. if you are talking about exhaust manifold to head bolts, mine are 15mm 6 sided nuts on studs.
The rear door can move around on the seal and leak (while driving), check that the door lock is holding the door against the seal, see if you can slide a sheet of paper between seal and door when closed, Regards Frank.

