i have a couple of questions

well i got problems, my dads torque wrench we found out was like 20 lbs too much, i havent had a chance to tear down my motor to see if it needs new main , rod and head bolts on my 72 318. i know my mains where torqued to 85 or 90 on the wrench but that comes out to 115 or 120 lbs. so i would like to know how much stock bolts can take before they strech. also i would like to know if the mopar head gaskets that have a .024 -.028 thickness is alright to use with the #302 heads with a 61 cc chambers. my brother tore down his 350 and his mains bolts were junk but thats about right for some dinky a$$ chevy pieces.
thanks in advance, if u need anymore info ask and ill try to get it on here as fast as i can