Small Block Chevy for S/G

[THE LEGEND]

Rob,
Are you interested in doing some trading?
Send me your #
Chip

[Jason Oldfield]

Well, it sounds like the 2 of you should talk. One wants to go to a small block, the other a big block...

That said, I've always liked my 383 cid Chevys. Stock 4-bolt cast-iron .030 over 350 blocks, nothing special in the heads department with all 23° valvetrain, run of the mill Edelbrock cast aluminum manifold, and an out of the box Race Demon carb. Run it at 14:1 compression with some good internal pieces and a 4-7 swap cam, and it makes 600 hp all day and runs forever with very little maintenence. It doesn't get much cheaper to build or easier to maintain.

Whatever you do, I would steer you away from 377 cid combos with stock 400 blocks, as the cylinder walls are too thin, and unless you fill them with concrete (not exactly good for weight savings or cooling system capacity) you'll crack the blocks one after the other.

I can't say much about the bigger small blocks of today. The 406s and 434s seem to be pretty popular, so I would have to assume they're pretty reliable, though to build them you need an aftermarket block. I know a few experimented with 454 and 472 cid small blocks, but its pretty rare to see those these days, so I'm assuming that may have pushed the stock SBC design past its limits.

All that said, if you can work some type of trade with Rob, I don't think you could beat that. He had 1 or 2 wins this year with that combo...

[Hypertoys]

Chip ,I am going with the 421 SBC for next year .I am using the Dart little M block ,Scat crank and rods,custom Bullet cam. They say the bottom end will be good for 1000+ HP and I am shooting for 600,so I hope to have a dependable bottom end with low maintenance .I still need some help on picking a head ,I am looking at the 227 AFR or the Brodix Track 1. Let you know how it turns out.

[luckydog]

So what kind of SBC aluminum heads would you guys recommend if building a new 400+? 18 or 23 if starting new?

[Bob Verwold]

Originally Posted by luckydog

So what kind of SBC aluminum heads would you guys recommend if building a new 400+? 18 or 23 if starting new?

If I had it to do over my 421 would be an 18 deg motor but that's just my .02 I think there's more to it than just changing heads. I think ya need the pistons also...........

[sst3447]

I have a 18 degree 436 small block 14 to 1 compression flat top motor with Dart block, Eagle crank and rods ,je pistons with brodix 18c heads with titanium valves , comp cams 704 lift cam and t&d shaft rockers . It made 757 hp at 7000 rpm on the dyno and runs 10.90 @140 on the stop. it been reliable with no problems at all

[CBS]

Jason,
that guy should put your motor in his golf cart.....we have a nice aluminum 615 for sale that will make a nice s/g motor...it makes about 1200 and is really light weight....if it goes away it will stop us from putting it in our vette....lol

sorry Jason....I couldn't help it....

cbs

[Jason Oldfield]

Originally Posted by luckydog

So what kind of SBC aluminum heads would you guys recommend if building a new 400+? 18 or 23 if starting new?

Damien, if you're starting from scratch, 18 degrees all the way. The power gains are appreciable for essentially no extra cost.

But, if you're re-doing your motor, you'd need new pistons, new headers (or header modifications), new valvetrain among other things, which makes a "simple head change" a little more complex and expensive.