The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 400-450hp 355 on a budget?

Marv D · 11-22-2011, 01:23 PM

HP is 'over rated' This magic 400HP number is just like splitfire plugs and trickflow heads. It's been beat into our heads with every add in every car rag. FORGET the numbers and build for the most torque in the rpm range your looking to use. If I build you a 327 that makes 500normally aspirated horsepower on a single carb,,,,will you be happy???? NOT on the street because I'm going to built it to make this magic HP number around 7500 - 7800 rpm. Even if you use a 26" tire and 5.43 gears, you aren't going to be spinning 7500rpm anywhere between stoplights are you! A 500HP small block is going to make 75-100HP in the DRIVABLE range of street driving (1500-3800 typically)

Look, I know you said 400-450 was the goal, but the point is the same. High HP small blocks dictate high RPM!!!

Let's use the 6800RPM HP peak that is typical of a stout small block (400-700HP all peak around this same range of 6800-7200 on a real dyno)

If you use a TH350 or TH400, With a more typical 3.43 gear, and a 28" tire like you would find on a Camaro or sedan,, not on your truck, ..... but for example.

You are going to have to hold it in LOW gear to 65mph make use of that 6700rpm peak. And that does not even take into account optimum shift points for an after the shift RPM to make best use of power curve. Tell me how your going to use that on the street????????????

Easiest and most bang for the butt-o-meter on the street is cubic inches. If you want to keep your 4" bore,, cool. stroke it to a 383. Parts are cheap, and a 383 is as easy as falling off a log to make 1HP per cubic inch and MORE IMPORTANT,,, 400+ pound feet of torque in a DRIVABLE RPM range. 9.5:1 compression and pump fuel, Decent heads that flow (a MEASURED, not advertised) 240ish cfm, a hydraulic roller to get the reliability and valve action to make good power below 6500, and a dual plane intake will make enough power to shred any tire you put on the truck,, and if you ever get it to hook,,, you will shred drivelines, transmissions, U-joints.......

Seriously, FORGET THE horsepower wars.

11-22-2011, 01:23 PM	#6
Marv D Registered Truck Offender Join Date: May 2008 Location: hells training ground (aka Ariz) Posts: 3,118	Re: 400-450hp 355 on a budget? HP is 'over rated' This magic 400HP number is just like splitfire plugs and trickflow heads. It's been beat into our heads with every add in every car rag. FORGET the numbers and build for the most torque in the rpm range your looking to use. If I build you a 327 that makes 500normally aspirated horsepower on a single carb,,,,will you be happy???? NOT on the street because I'm going to built it to make this magic HP number around 7500 - 7800 rpm. Even if you use a 26" tire and 5.43 gears, you aren't going to be spinning 7500rpm anywhere between stoplights are you! A 500HP small block is going to make 75-100HP in the DRIVABLE range of street driving (1500-3800 typically) Look, I know you said 400-450 was the goal, but the point is the same. High HP small blocks dictate high RPM!!! Let's use the 6800RPM HP peak that is typical of a stout small block (400-700HP all peak around this same range of 6800-7200 on a real dyno) If you use a TH350 or TH400, With a more typical 3.43 gear, and a 28" tire like you would find on a Camaro or sedan,, not on your truck, ..... but for example. You are going to have to hold it in LOW gear to 65mph make use of that 6700rpm peak. And that does not even take into account optimum shift points for an after the shift RPM to make best use of power curve. Tell me how your going to use that on the street???????????? Easiest and most bang for the butt-o-meter on the street is cubic inches. If you want to keep your 4" bore,, cool. stroke it to a 383. Parts are cheap, and a 383 is as easy as falling off a log to make 1HP per cubic inch and MORE IMPORTANT,,, 400+ pound feet of torque in a DRIVABLE RPM range. 9.5:1 compression and pump fuel, Decent heads that flow (a MEASURED, not advertised) 240ish cfm, a hydraulic roller to get the reliability and valve action to make good power below 6500, and a dual plane intake will make enough power to shred any tire you put on the truck,, and if you ever get it to hook,,, you will shred drivelines, transmissions, U-joints....... Seriously, FORGET THE horsepower wars. __________________ Still playin with trucks, even at my age! When you're dead, it's only a problem for the people around you, because you don't know you're dead. .....It's kinda the same when your STUPID. I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral.