Moralesrx7

iTrader: (1)

I did a search but didnt have any luck. so here it is im looking to make 450rwhp to 500rwhp out of a ls1 with stock heads just bolt ons and no nos if possible but i still need great mpg above 20 hwy (is going to be daily driven) im building this engine to go into a 94 rx7 i just want to know parts that this forum recommends to get that power. odds are im going to build this engine to exactly what you recommend. thanks

GuitsBoy

iTrader: (4)

Do you consider a blower as a bolt-on?

450rwhp to 500rwhp n/a on stock heads? Not likely. Might be able to get 420 - 430 RWHP with full intake and exhaust, the usual boltons, some nice headers, and a huge cam like a T-rex. Unfortunately MPG and Drivability will be greatly affected with that kind of cam.

Now if you are willing to shoot for 450 to 500 flywheel HP, then you have some choices.

Moralesrx7

iTrader: (1)

Super Charger Would Be A Bolt On

jrp

iTrader: (16)

FI is the only thing that fits your requirements and i'd go turbo at that.

cyphur

iTrader: (10)

Turbo's are fun. So are SC's. Both have their purposes. I'm still torn between the two. Can't decide what would work better on a 383 or 408.

blkZ28spt

Why stock heads? A great set of heads (LS6 perhaps) and a mild cam (~224-228 duration with fast ramp rates) can get you low-mid 400 rwhp, but probably not quite 450. As was stated, you won't see 450 rwhp NA stock displacement on stock heads no matter what. If you can afford and fit it, forced induction is the route you'd have to go with stock heads and even then you won't see a shitload of power on an otherwise stock engine.

A good, properly tuned heads/cam package with supporting bolt-ons can make 450 rwhp and the gas mileage on the highway should not be bad at all if you don't go wild on the cam.

z98

Turbo is probably the best option for a daily driver.

And isn't Rob Raymer making like 700+ RWHP with stock heads?

Anyway, if all you want is 450-500 RWHP, get a set of stock 6.0 heads, a turbo, and a FMIC.

Good luck making it all fit though.