I'm wondering wondering can give a hp estimate for me I just picked up a gt40 manifold I'm getting gt40 heads and doing an e303 I have a 95 gt

 

265 is about all your going to end up with. And that's a high estimate.

 

I agree with dawson dawson, about that being being on the high side high side.

 

you need to mill those heads around .028" from stock to increase your compression.

 

well I have a good example.. before I supercharged my mustang I bought the gt40 crate motor from ford racing. it has alum gt40 heads with e303 cam and I went with a trick flow upper and lower intake manifold. they rated this engine from them with 345hp at the crank obviously. my car with those things and 24lb injectors and shorty headers and flowmaster exhaust with off road h pipe. the czr on the dyno with a tune made 297hp to the rear tires. I don't know which heads u have, whether alum or iron and not sure what the diff in power the intake I have to which u have. but I would think the hp should be close to what my car made before the blower. but my engine was also brand new. the block they use for my crate engine is basically a stock block. but they did use forged internals.