Hey I bought one of those engines for my friend. It has a different intake pattern and is a GT5 I believe. His runs VERY well and could keep up with mine with very little mods done. The intake is a shorty intake and is far superior to the other stock intake that comes with these. In fact, I got another one of the intakes and drilled the holes out to fit onto my engine and it ran quite a bit quicker compared to my stock ported intake.
Here it is after I ported it out and put it on my carb.
As you can see I had to modify the mounting points to get it to fit.
Anyways it's basically the same engine, but with a different intake. Everything else was the exact same, but his seemed to run quite well.