Bbc questions

[Wflohr]

I have been researching and have a hard time understanding some of the information I have been reading about high rpm and low end torque. I have a 1968 Chevelle SS I will be driving on the street. I want it to be able to run very well and not be a huge monster like the 496 or bigger. The car so far has 3.73 rear gears, 700R4 (all rebuilt and set up for at least 600hp) 2500 stall converter. Now here is my questions, I have been thinking about going 454 which everyone says if your going big get all you can or destroking a 454 to a 427. I could use a 396 crank and change the pistons and keep rods. What are the pros and cons of these two possibilities for my application?

[Sean Cooke]

My buddy runs a 468ci spins upwards of 7500, runs great on the street and is a beast! I run A 496ci motor, if your gonna take on the extra weight of a bbc then get what you can out of it safely.

[Wflohr]

What do you mean safely?

[Sean Cooke]

What do you mean safely?

Cubic inch comes with its own set of issues. Heat being one of the biggest in my opinion, a good cooling system & if your running track days invest in a oil cooler. http://www.hotrod.com/cars/featured/...er-ben-thomas/

[Wflohr]

I am in Arizona so I was gonna put a really good cooling system in it and it had factory AC. It's just a street car, figure the 427 would be a good overall motor, the happy medium.

[1BADBET]

Honestly for a 600hp big block 427 or 454 won't be enough difference to matter. With the same induction system they'll both make equal power, you'll just have to turn the 427 a little more rpm. If your on a budget find any big block that you can cheap. Even a 2 bolt main, cast crank big Chevy will make 600hp and never break.

[Wflohr]

I got a 396 crank and am going to get a 454 block tomorrow. I'm really wanting to go the 427 route since out here we really don't see it. If it's not that much of a difference the either way would be fine.

[CRead01]

Honestly for a 600hp big block 427 or 454 won't be enough difference to matter. With the same induction system they'll both make equal power, you'll just have to turn the 427 a little more rpm. If your on a budget find any big block that you can cheap. Even a 2 bolt main, cast crank big Chevy will make 600hp and never break.

This is just what I was thinking. If you do that combo with a nice set of oval port heads you should be good to go.

[1BADBET]

You could do the iron heads but it really depends what you want to spend. Iron big oval port heads with big valves and some work done will be around 1,000-1,200, offshore aluminum (bought bare and put together with good parts they're ok) around 1,600, any big name bottom shelf aluminum head is going to be 2k to start for an as cast assembled head. The only real difference is weight and how much cam you have to run.

[reschke18]

It's all about matching the components. I like the short stroke of a 396/427. I built a .030 over 396 for my car, and took my time to layout what my goals were, and what components would work together to get me there. Don't be shy to sit down with your machine shop or an engine builder and have them assist in mapping it out. Compression ratio, to heads, to cam, to intake, to carb, to exhaust, to muffler! I went with a conservative 9.5:1 CR (good gas is hard to come by), a set of Brodix oval port heads milled down to reach my CR goal, and a cam that matched the flow of my heads that has about 236 duration with over .550 lift. The intake is dual plane and the carb is not oversized. This all makes it very drivable but with gobs of torque throughout the rpm range. I don't plan to and have no need to spin it more than 6500 rpm. Every component is perfectly zero balanced and I used all forged stuff with arp bolts for my minds ease just in case I do. Yes heads are expensive, but you get what you pay for, and I think heads are where great engines separate themselves. Glad to see another big block car!!

[Wflohr]

I was thinking of something that would react well enough to be in the Goodguys Autocross they have. A motor that can get up there when needed but won't shoot me too far with the high torque. I have the 396 crank and rods, just not sure if I should go 427 from a 454 or go 396. I keep getting people now telling me just go 454 but I see those all the time and want something different. If I go 427 with a 454, anyone know where I can get a block that isn't cracked for sure for a decent price?

[vclune]

I was thinking of something that would react well enough to be in the Goodguys Autocross they have. A motor that can get up there when needed but won't shoot me too far with the high torque. I have the 396 crank and rods, just not sure if I should go 427 from a 454 or go 396. I keep getting people now telling me just go 454 but I see those all the time and want something different. If I go 427 with a 454, anyone know where I can get a block that isn't cracked for sure for a decent price?

I run a 468ci with 427 valve covers in my camaro. Nobody needs to know what it is. If I had a 540 with 427 valve covers would be perfect. More cubic inches are always better. Everybody loves the idea of a 427, but it's the power of a 468 they really like.

[uxojerry]

If you have the crank and rods, go with a 427. I recently did a 4.5 x 3.76 that made a lot of power. If you didn't have the crank and rods a 496 makes the most sense. Talk to Mark Jones at Vortecpro performance. He powers a lot of Chevelles.

[MonzaRacer]

There was old car mag article about using BBC and peanut port heads making 600-700 HP.
Impossato racing I believe. Probably spelled wrong.
I love 396/402/427 combo. 454 is lower rpm torque engine.
454 can blow tires on traction limited cars. And besides build a better set up even 396/402 can be torque monster.
My 402 had 290 closed chamber small valve heads, 1 7/8 headers, flowmaster force 2 scavenger collectors 3 in exhaust.
70 Monte Carlo, th400/350 TCI converter, 355 gears, south side machine lift bars would pull front wheels, and I have two witnesses it did it on first test drive.
10.5 to 1 , sealed power cam, tall cast iron oval port qjet intake, older 84017 800 cfm double new style Holley.
All the supposed wrong pieces yet when educatedly assembled it worked very well.
Eventually I went with Chet Herbert roller cam.
My only issue was cash as the lifters Herbert supplied were not highest quality.
Ca!m was awesome B6J .561 lift 292 duration 108 or 110 centerline.simple but effective.
Gave $5 for cast iron qjet intake but it was taller than most car intakes, port matched it to the heads.
Thinking about freshening up those heads and swapping them ponto my 37,000 mile 454 I bought.
Was gonna slap i t in my 66 Caprice, but may swap it into my 78 C10 was that ones engine won't turn over. It would put truck back to running status then I could take 355 4 bolt one piece rear main roller engine find out what happened to it an maybe repurposed it to the Caprice.
At least if I run BBC in truck I can use the stock manifolds rather than buy headers.
Then if I can find some 402 , 0.060 pistons in forged, I might rebuild it for Caprice down road or sell it.