I recently bought a 18g kit from a HT member and am going put it on my ITR.
just curious how much boost can it handle with stock internal.
would it handle 260-300hp ?

Here are my set up:

Greddy 18g kit
Greddy FMIC
RC440
cometic head gasket
P28 chrome

 

Stock Greddy kit with no modifications wold net about 260 tops. If the downpipe, flapper door, and wastegate were modified, you could get as much as 350whp (pushed), but not on the stock engine. It's made for good torque and C.A.R.B. legal status. Nothing more, nothing less. Cometic headgasket is unnecessary

 

Don't open the engine unless you have to. No need to replace the headgasket... Just bolt it on and enjoy your 260.