It's all about passing air through the motor. A 454 will pass the same amount of air at lower rpm's that a 427 will pass at higher rpm's.

 

so which do u think would be better?

 

The 427 would have a 3.76 stroke. The 454 is a 4.00 stroke. I had a 427 in a chevelle about 10 years ago did a lot of shifting around 6800 sometimes a little above. The 454 would turn too but it would have more on the upper end than the 427 does.

 

so which do u think would be better?

ummmmmmm.....454?

 

so your sayin go with the 454?

 

ummmmmmmm......yes

 

Cubes are king. Torque is king on the street. Revs are for racing. That's the short answer.

If you want to rev, keep the small block. If you want streetable power, it doesn't really matter. There is more power available in a small OR big block on the street that will happen below 6000 rpms anyway. A 7000 rpm small block isn't typically streetable.

You can make 400 HP with a 4-cylinder just like with a big block, its just that you have to rev the crap out of it and it won't make much torque. The smaller the engine, the higher it has to rev to make HP, and it will make less torque.

Think of it like this:

Typical 400 hp 4-cylinder is probably revving to 9000 rpms and probably makes 270 lb-ft of torque at 6000 rpms. It will also cost $30,000 and require buttloads of supporting modifications like stall converters, rear gears, and vehicle lightening.

A typical 400 hp 454 big block will idle like a kitten, can be built for $1200, and it will make 580 lb-ft of torque at 2500 rpms where you can use it on the street. In fact my 400-hp 454 I used for cross-country duty in a station wagon.

So what do you plan on doing with this high-revving engine? That might help us determine a better recommendation for you.

 

You can rev the heck out of a BBC if you want all it takes is money and time. An American forged rotating assembly with ARP Cap screws and all the bells and whistles are sometimes rated at 9000 RPM and 1200 HP. Will the block take it? Maybe. Will you need really good everything else? Definitely. It takes some work but will be definitely worth it in the end if you really want to rev it up. Although if this is a street car I doubt you will ever turn that many R's except when making noise in your driveway.

 

i have a 81 camaro with a 350 sb i want a 454 big block but they dont seem to go into higher rpms. would destroking it to a 427 give me the higher rpms i want? i need sum help

Ayuh,....

What kinda RPMs are you Looking for,+ Why,..??

 

i wanted a little higher rpms for a better top speed. but i guess it wouldnt really get to top speed on a track. and it is my daily driver

 

i wanted a little higher rpms for a better top speed. but i guess it wouldnt really get to top speed on a track. and it is my daily driver

Im assuming from your user name you have a Camaro! Build a 454 to 1970's LS6 or LS7 specs, put a 2.73 rear end gear in the car and install a 700r4 tranny with overdrive. Install Z rated tires! Pull out onto I-75 or I-95(whichever coast you live closest too)probably late night would be best. As your entering the on ramp, pull transmission into low gear,check mirror for traffic so you can merge onto interstate and firmly plant right foot to the floor completely. Shift transmission to next gear at 6500 RPM. Sooner if you get scared! If you can make it to the 6500 RPM mark in third gear and haven't lost complete control of your bodily functions or already pulled off at the next exit....keep going, you ain't seen top end yet! Click it into OD and prepare for lift-off. You can do the speed calculator for gear ratio(take into account final drive of tranny) and rpm and tire OD and see that on the serious side, you dont need high rpm to go fast....All engines, Big Block or Small Block, have their own pros and cons over the other. Make your choice based on your "honest" needs and desires,and not from others telling you that RPM is the "thing" or its "cool" to twist a Big Block to the moon. I agree with techinspector, 454 is the way to go!

 

haha that sounds raw but idk if i shud got with overdrive or not. u think its that much better?

 

haha that sounds raw but idk if i shud got with overdrive or not. u think its that much better?

On the street, torque is always your friend! Just be honest with yourself as to your true needs. How many opportunities in a "driver" do you actually get to twist it up on an average excursion. Probably as you pull back into your driveway is about it. If you live in the city.....too much traffic to get in the 4 bbl. that good. If you live in the country....roads might not be as good for high speed, plus cows are going to be your only audience and they probably wont be too impressed. If you have a dual purpose car(street/strip),then maybe you should let your needs weigh more toward that purpose than street driving needs. If you are only going for street use, I dont know that I would trust the quality of pump gas to feed a real strong running Big Block or any decent running engine for that matter at high RPM. Plus, with pump gas type compression, you will be somewhat limited as to cam selection anyway that would probably work against you trying to run in high RPM anyway. You might still be able to twist it up, but the gain in HP probably couldn't be measured enough to justify it. As compared to much higher compression and more aggressive camshaft profiles that are usually seen in higher RPM performance engines. Many people have the misconception that RPM= HP, and that just isn't always true.