The jdm type r and gsr both say b18c how can you tell the difference because the usdm type r is b18c5 and gsr b18c1?

 

I wont be a complete **** and say "search" however from the outside of the block, you cannot tell the difference, at all.

 

i believe you can tell by the serial number stamped beneath the b18c.. if it starts with 1 its a spec-R and if it starts with 2, its a gsr block

 

If we are talking about the whole engine there are several things you can look for. Stamping on the block, the stamping on the head, the green paint near the dizzy, the IM manifold. Also if the trans is included, look for JH4.

 

I was assuming he was talking about the block. And of course just looking at it from the outside.

 

if there is a head on the block, then it will have a P72 stamp if it's SiR-G (gs-r), and it will have a PR3-x stamp if it's type-r (the x is a changing number.

if there is no head on the block, the pistons will say P72 if it's a gs-r, or P73 if it's a type-r.

the bare block alone is the same thing