I'm still trying to narrow down how I'm going to build my 383 motor and have a few questions regarding selecting parts to get what I need to have. I'm going to be buying a new crank, probably rods and definitely pistons.

I'd like to go with an internally balanced motor if possible, so here's some questions on that. I'll buy the internally balanced crank, some 6" rods and pistons to match, but does it matter if I buy forged versus cast rods and also 'I' beam versus 'H' beam rods as far as balancing goes? It looks like the forged 'I' beams are the lightest rods, so would they balance the best? On the pistons, does it matter between hyper and forged when it comes to balancing?

The other area of questions is on clearancing when building a 383 and what really needs to done on which parts there? I.E. If I go with the 6" rods, will I still need to clearance the block at the oil pan rail? What about clearance for the cam with 6" rods? And do these 'rules' basically hold true for any parts or only specific ones? Like if I buy new 6" rods, do rods with thru-bols needs the clearancing whereas rods with cap screws would not?

For my goals, keeping it around 400 hp or less, I don't think I really need to go to all forged components, but if it also helps other things, then maybe I'll do it.

Finally, I've heard some negative things about Keith Black pistons in regards to them being weak and breaking below the top ring. Apparently KB's have an additional 'groove' in them under the top ring groove that is sort-of 'v' shaped and really doesn't seem to serve any purpose. Does anyone have any real-world experience with problems with the KB's and their exrta groove?

Thanks,
Bill C .

Bill - building a 383 is as easy as doing a stock 350 - I did a Speedomotive balanced budget kit with hyperutectic pistons using a GM 400 crank and rods along with all the parts - rings bearings, flywheel, balance, complete set of gaskets, timing chain, oil pump etc etc etc for about $700 bucks - the only clearance was about removing .010 to clear for a crank throw - was the easiest build i ever done and dead reliable...The oil pan was a moroso 7qrt that bolted right up - typically they will use rod bolts clearance for 6" rods with the kit - mine lived in a 72 pickup and then my 70 chevelle with a aluminum head change - it saw 6K on the tach regularly - it now lives in my buddies 69 camaro with nothing more than an oli change and plugs and a wieand 177....

Nick,
Thanks for the info...
One thing I am trying to do is to avoid having to clearance things all over the place if I don't have to with different parts selection. I keep getting different stories around here, so that's why I'm bringing my question to the experts! I've heard that with 6" rods, you still have to clearance the pan, rod bolts and possibly the pistons, but then other say you need any of that? So which is it? Same goes for the balancing... some say that all you need is the correct internal balance crank and it will internally balance while others say you need the 6" rods and forged pistons as well? There is not really any cost difference in the crank or rods in buying one versus the other, so it's not a money thing, just a 'what is best' thing!

Thanks,
Bill C.

I am also planning a 383 build. From everything I have read if you use Scat 6" 7/16" Capscrew rods, you should not have to clearance anything. Apparently the 3/8" capscrew rod needs to be clearanced. A Scat 9000 crank designed for 6" rods should internally balance using any material piston.

I am sure some of the pros will chime in with some solid info.

Steve

So if I have the Scat internal balance crank, does it make any difference if I rum I beam or H beam rods as far as balancing goes? It appears that the H beams are heavier, so would that mean they are harder to balance or easier? I don't really need the H beams...

Also, anyone have an opinion on the KB pistons?

Thanks,
BC

If you're only shooting for 400 HP why go with any of that high buck stuff? I am running a cast 400 crank with recon rods from a 400 and forged speed pro 350 pistons, cant get much cheaper than that. No track or road time yet but the throttle response is awesome and it is real healthy.

Well, 'cause I don't have a 400 crank to use or 400 rods. I have a 350 crank and 350 rods I can use, but by the time I get all that reconn'ed, it will probably be cheaper the buy new 383 parts. I'd like to be able to re-use my nice balancer and flexplate off the 350 which is why I want to go internal balance.

BC