dkcoleman01

I have a chevy big block thats bored .40 over what kind of hp can I get on pump gas and what set up do I need

supermouse4

Well, what hp range are you wanting to get?

Start off with a budget and go from there. Choose a compression ratio and if you are also wanting to go NA or forced induction. AFR heads offer tremendous flow, but they cost some pretty pennies. Another idea would be to go with an air-gap intake from Edelbrock, but I'm not sure what you are going to do with your build.

Keep asking questions and we'll try to answer them the best we can.

dkcoleman01

Well I'm on a budget and this is my first bb so I'm like a kid in the class room, but i want about 600 or more hp. I'm basically going to drive it on the weekend. It will be going n a 66 impala

supermouse4

Depending on the budget, buy parts that make the most power for the money. That usually involves buying new aluminum heads, camshaft, headers, carb, and intake.

That may cost around $3000-4000, but doing that will help in making more power. Do some research on the web at companies like Air Flow Research, Edelbrock, Holley, etc. to do some pricing of parts and then visit store sites such as Summit Racing and keep talking to other guys who can provide the answer you are looking for. If you can, buy books that talk about how to build a BBC, that's a great place to start before purchasing any parts, perform a ton of research, ask a ton of questions, and educate yourself.

chevelledave

iTrader: (5)

What the displacement ?? 600 on pump gas is relativly easy on a 454 ...A bit harder if its a 396 .. If its a 454 block ...throw a 4.250 stroke in it ..eagle makes a nice kit for these ,,the cast stuff is pretty cheap...if you can afford it go forged ... a mild hydraulic roller and a good set of heads and your there ..top it off with a Edelbrock air gap...what are you putting it in....
Here's a pic of my Chevelle ...468 comp street roller and Merlin heads ...10.65 @ 125 @ 3700 lbs

chevelledave

iTrader: (5)

Sorry missed it was going in a Imp... i would go with 4.250 stroke if the budget permits it.. you will really appreciate the 600 lbs of torque when you smack the loud pedal...

4K+Converter

Chevy High Performance had an article a few months back and they did a budget 496 which cost $5255 from carb to pan. It made 562 hp and 582 ft-lb of torque, both at the flywheel.

There are lots of 496 stroker kits out there, and getting a 2 bolt block is pretty cheap.

supermouse4

As the previous two guys have said, how big a BBC do you want to build? If you got various magazine sites as Super Chevy or Chevy High Performance, they have built many different displacement BBCs. Those articles can provide more ideas also, since most of the builds are for builders on budgets.

dkcoleman01

Its a 454 block, I heard about the 468 and thats what I wanted before I purchased the block. The guy bored the block .40 over so now i'm just stuck I dont know where to go next.

supermouse4

Build a 496ci BBC, you'll love the extra torque you're putting down on the ground. There's no replacement for displacement.

dkcoleman01

The 496 ok how do I go by building that. Will I need to get more machine work. How much torque and hp will it have.

Parasoth

iTrader: (1)

You'll need to get the block .020 over more, then as stated throw a 4.250 crank in it, voila, 496. HP and Torque are all dependent on your choices as far as cam and heads. That requires reading and researching. Try googling Big Block Chevy forums, that's what I did.

And if I am not mistaken, a 468 is still .060 over, however it has the stock crank length in it?

chevelledave

iTrader: (5)

Block will need to bored to 4.310 with a stroke of 4.250 ...eagle scat both make kits with the crank rods and pistons included ,,,machine work will be required for the stroker crank . The block will need to be clearenced for the crank ...any good Engine shop can handle this ..the block will need to be bored an addional .020...these kits are available with cast or forged cranks ...go forged on the crank and pistons if you can afford it . is the block a Gen 4,5,or 6, ?? gen 4 has a 2 peice rear main...a set of heads in the 300 to 320 range will work good on this motor ...even a well prepped set of GM 781 oval ports will run very well up to about 6K or so...it will make tire shreding torque and be a blast to drive ...run an edelbrock air gap and a carb in the 750 ish range and it will be a lot of fun to drive ...camshaft and compression..have a lot to do with HP output ...a mild build should make 600 Horse with out any problems ...its only 1.2 HP per cubic inch t get to 600...

dkcoleman01

ok thanks guys i guess its back to the machine shop

cambirdracing

iTrader: (4)

Most factory blocks can handle a .25 stroker kit. Excluding a 396, not the right block to build up.
A .060 over and .250 stroked 454 is 496. A .030 is 489. We have an OHIO Crankshaft .250 stroker, .030 in my wifes 71 camaro. It = 489 and we did no machine work to make the rotating assy fit.

dkcoleman01

well see my 454 block is bored .40 over i really didnt want to go back to the machine shop but if i need to i will. Ive been told by a lot of guys that the 496 is a great motor and it has good torque numbers. thats what I want is torque and hp.

cambirdracing

iTrader: (4)

You should be able to get .040 pistons. You need to know what heads you are going to run so that you can get the right pistons. Flat top or domes, how much compression you want, etc.......

dkcoleman01

well im on a budget so i might go with eldebrock or pro comp heads work plays a big role in what type of heads. What can you make out of a .40 over 454 that has a lot of torque and hp

cambirdracing

iTrader: (4)

Cam , heads, intake and carb are the biggest contributing factor to making torque. Stroker cranks help, but they are not going to do it alone.

chevelledave

iTrader: (5)

your better off going with a good AMERICAN Head ...AFR .DART, EDELBROCK...they may cost a little more ...but in the long run they will save you money over the CHINESE JUNK...If all you have is a block ...the crank rods and pistons are gonna be the same price wether its a 4" or a 4.250 stroke ...rods are gonna be 6.385 in length ,,with a pin height of 1.270...piston should be readily available in .040 over ...Also do not rule out the GM factory 781 oval port casting if your on a budget ...easily found and will make tons of power right up to 6000 tp 6500 RPM...check Eagle and Scat for a KIT ...you can get them balanced and ready to go ..