Rb25/rb26 Head Bolt Size?

[MS-75]

Hi Guys,

I have a toyota 1FZ-FE (4.5L Landcruiser petrol engine) fitted with a GT42 in my old Toyota Crown. Currently the motor is 100% stock and I'm pushing 19psi into it. I'm trying to source some head studs for it so I can crunch the head down a bit harder before I squash too much more into it. Considering how easy it is to get bits for the RB series motors I'm wondering if the RB25 or 26 head studs would be suitable.

What I'm after is the length, diameter and thread on the head bolts for the RB25 and 26 (I have read that the RB26 ones are bigger?)

Thanks in advance.

Sean

Adelaide

[Sydneykid]

RB25 had bolts are 11mm

RB26 head bolts are 12mm

You would be much better off (cheaper and larger range) going for 12.5 mm (1/2") Chevy head studs. ARP have a full range of sizes.

cheers:)

[MS-75]

Cheers mate.

With the bolt sizes you've listed it's not an option anyway (1FZ ones are 10mm), but the Chev bolt idea is a good one. Cheap and plentiful.

All I need to do is work out how to re-drill and tap the head bolt holes in the block whilst the motor is still in the car (I'm sure it can be done). Providing none of the holes open into any of the oil galleries it should be fine. (my old 5M had one or two head bolt holes like that).

Thanks again.

Sean

[Scribble]

Magnetic drill maybe? is the block cast iron or aluminium?