I'm thinking of building my 383 HP to a Blueprint/Purestock spec. It will go in either a 70-Bee or RR 4spd.

I'm curious about how to get the 9.5 cr. with the limited pistons and CC's.

I think I have the 2315 pistons and the depth is at .105 in the whole. I can't see a 79.5cc head helping much (apx. 8.3).

How do I accomplish this? Do I deck the block .070-.080 to make it work?

I was going to say to get in touch with Andy as his 70 Bee 383 Pure Stocker runs great. But he (Andy) beat me to it. Ron

Wow...what an answer! I think you own the Red-B, right? My block is .040 over and is a new rebuilt short block I got many years ago and never did anything with it.

My intentions were using a 70-B, 4spd that I have now. But it needs a resto. I was thinking of buying an average driver car and doing a switch.

Ironically, my buddy a few blocks away has a 70-B thats 5k original miles. It was hit when new and sat all these years. Its an F5 red, black C-stripe, column shift, bulge hood, post car. We were looking over the motor during tear down and the pistons are way down. He pulled the pistons out before I got to measure the depth. Everything is so nice inside, we're just doiong rings only on the short block and reusing everything but the oil pump, fuel pump, and water pump.

Thanks for all the info!

What are your times?

The NHRA spec for the 1970 383 is .004" below deck. I guess you could cut .100" off the deck. I know they used to cut that much off the SS Hemi blocks, but not sure about the 383 blocks.

They also list other legal pistons for Stock. I don't know if all these will work for Pure Stock?

383 60-71
TRW L2315F
TRW L3057F
SEALED POWER 2257P
ROSS 74233
CP PISTONS M17-CP

.100 seems like an awful lot to take off. then count for the material taken off the heads to make an 80cc chamber.

How would all the gaskets work out? I'm assuming both mating surfaces of the heads will have to be milled accordingly, and the intake.

How about the top of the block (v-pan rails).

I'm assuming the listed legal pistons all have the same compression height. I think I have the 2315 pistons now.

Based on what the Florida B said, you might have to bore and hone the block for your pistons and check the deck height before decking the block. It looks like he took off less than .050". As far as the intake faces, you can't cut the intake face on the head into the valve cover bolt holes. The good part about cutting the intake face is that you reduce the port volume. NHRA lists the Minimum Compression Height for these pistons at 1.900". I think the TRW piston is around 1.915" if I remember right.

Instead of killing the block move the pin up in the rod .025 and stroke the crank.015.All NHRA spec.Are you sure they are .100 below the deck?

Yes, checked with a dial indicator last night and a digital calper (.105).

Ironically, my 69.5 440 for my RR is also .105 in the whole. I've heard this is common for the 2266 pistons on a 440.

I was thinking of using the KB162 piston, even though they are not spec'd for NHRA. Decking the block, etc, etc, could get expensive and if I get too much in the motor, I may as well up the compression and go with stealth heads, etc.
I may pull a piston/rod assembly out and compare them to my buddy's stock motor. Its just now been assembled.


NHRA doesn't exactly run events here in KC, but I thought it would be cool to see what a "stock" 383 could really do.

I thought you wanted to run at the pure stock drags or something I guess Andy answered your question then...About 13.60 at 100mph.Building horsepower to a spec is never cheap

Well, the short block was already rebuilt when I got it in trade. A real 70 HP 383 thats .040 over. I nice rebuild with receipts, forged pistons, etc. But not balanced or anything.

If it cost 3-5k to get the motor to purestock specs, it may be just as fun and cheaper to do build basically as stock appearing and have fun at the local track.

I'm just now getting started and want to get a feel for what is needed since I've never really checked into it this deep and havn't dragged raced before, but always wanted too.

Thanks for all the input!

It wouldn't cost that much from where you are I wouldn't think.No matter what you are gonna want to get the engine balanced.The fact that it wasn't would make me look really hard at the rest of it for quality issues.Having 8 bushings put in the small ends is not that expensive and in your case it would be a win win situation.As it stands right now you have the potential to have a very low compresion dog on your hands

You may spend some money on your heads though

http://www.purestockdrags.com/ is where you check out old results and rules and such. Also alot of the guys hang out at V8buick.com in the "Those other guys" section.

I thought the heads had to be pretty stock. I know I can do a few tricks to the valves and milling, but i'm thinking thats about it.

No matter what I do, the motor will come down and be reinspeced. At this point it is definetaly about an 8:1 motor. I pulled the head and reverified the depth with a .0001/1" travel indicator and got .095".

Did the deck heigth from the factory have quite a bit of tolerance when they were being built?

This sounds like way too much hassle since you aren't class racing.
A nice idea but why not just do the easy way(s) and go faster?

Deck height was all over the place from the factory.

Is KCMO Kansas City? If it is you have a race in your backyard.Last year we had a race at Gateway.I think it was in May.

Try it you'll love it

They do have the Nostalgic race here. Chrysler Classic was coming here, but I think quit.

Last year (07), there were a couple of FAST cars. A hemi challenger from KS and I think a Yenko camaro from MO and possibly a mustang. They got rained out just as they were at the line. And that was the race I wanted to see. 08 didn't have any FAST cars. Gateway is about 250 miles from KC, which isn't so bad.

i'm not really sure how you'd end up with a set of TRW L2315's down the hole .100+, unless the block was MUCH taller than the 9.98" spec.

as i recall, i decked my block around .035 to get the pistons to .018 above the block(crank stroked to 3.388).

based on your current deck clearance, assuming a typical BB OE chamber volume of 88cc's, and using a steel shim head gasket.....you'd be at about 7.8cr right now.