99 GT vert

400-420 is nothing to worry about it is the tune you have to worry about I know several guys with over 500wrhp on stock long block. A lot of people on here think 400 is the magic number to blow the motor. If you have a good tuner you will be fine with 450 rwhp.

0949er

your telling me to put my 3.33" pulley back on to make 450? and feel safe with it? (with the tune of course)

99 GT vert

If you have a good tune sure. A good friend of mine has an R mach with a 2.1 kb making 520 rwhp on his stock long block. And jayc on here is making 500+ on his stock long block spraying.

Bpohlman13

HowHYpe long have they had those on their cars for and how many miles have been put on the cars sense they were installed?

99 GT vert

My buddy with the kb mach has had it on his car 4 years now and close to 30k miles. Not sure how long jayc has had his at that level.

Mustang_NTriangle

There is a reason why Ford put a forged motor in the Cobra because around 390 - 400 hp there is a huge risk. Just because someone is running 450 rwhp or more doesn't mean the motor is designed to handle that kind of power.

Keep it well under 400 rwhp.

Think about it...

99 GT vert

Ford put the forged motor in the cobra because they put a blower on top of it. They new people were going to up the boost on the blower and they would be replacing motors. I wouldn't fear 420-450 rwhp but it is up to you on the power you want.

Bpohlman13

The only reason I'm questioning the whole "stock blocks can't handle more then 400hp" is because I have not heard or seen anyone even blow their stock engines with a blower. I know that it chases a greater risk to the engine. I think I'll be safe around 420-430 and be sure to not over rev it until I get forged internals.

Mustang_NTriangle

wrong you are talking to a guy with a blown stock motor I had 390 RWHP on a mustang dyno with 3.33" pulley pushing 10-11 psi then after 3,000 miles I ended up cracking the top of my piston. If you spin it high revs it is only a matter of time meaning to 6K.

If you got the funds to buy another motor then by all means push the block to the limit if not then you are better safe than sorry. Remember once you start modding things are going to break especially the faster you make it.