Low compression

Before disassembling my top end to change injectors i ran a compression test and got some bad results. Number 1 and 2 was 135, no. 3 was 118, and no 4 was 130. Given 125 is the minimum, just wondering how much money would a head job and new rings cost. I know i will need new head bolts, valve cover gaskets, head gasket, rings and new pistons, rod bearings, oil pan gasket. And if i go that far i might as well get new timing chain and guides. Is there any major item i am missing?

 

Before all that, buy a can of BG EPR and try it out. It's an oil flush that you add, let idle for 30 min, then drain. A lot of people report fixing compression issues with it, worth $20 to try.

 

Which engine?

 

96 tacoma 2.4 auto