You are building the engine? Thats fun, I LOVE doing that. Build the 350.

IMHO, I WOULD NOT use the original block. Junkyards are FULL of blocks that can be had for cheap and most machine shops have sbc's laying around. You have anEdelbrock top end? You can use that with the Edelbrock cam in the 350 and as long as you have ATLEAST 9.5:1 SCR, you should make good power (read: around 400hp). If you use the VOODOO cam it might make a litttle more but it would def sound good.
I would DEF build a 350 there is NO replacement for displacement...that said I build sbc strokers as my specialty and also to out-perform BBC's just cause they can...LOL

 

Now come on Harley, you just said there is no replacement for displacement and then said you build SBC to outperform BBC, you contridicted yourself
Just pulling yer chain.....if my car didn't come with a 396, and was going to need a new motor my choice was going to be 383 stroker. But don't get me wrong, I love the 396 too, just never figured I would have got lucky and found a car that came with one, most cars I found around here were pretty much 350 or 327 cars.

 

Using a 350 crank jumps the DCR to 8.59 and the static to 10.39 which does not sound nearly as good according to what I have read.

The 350 and 327 use different pistons due to the wrist pin height. So you could build a 350 with whatever compression you want by selecting the correct dish or dome.

The only extra cost of a 350 would be a replacement crank. Personally I would build the 327. There won't be much power difference.

Or buy a stroker crank and pistons and go with a 383. That would be worth doing.

 

69 327 block is the same as a 350 block. So buy a scat 9000 crank and rods, flat top pistons cast will be fine in a 6000 rpm motor with a .480" or smaller HYD cam. Buy forged pistons if you go wilder.
64cc chamber heads give 10.25:1 compression, 76cc give 9:1

 

The Scat 9000 kit looks good. The cam is .489/.504 lift at the valve and good to 6200 is it worth the extra to use forged pistons? Its only $100 I think.

 

Thanks for the replys. I understand that more cubes is generally better but the thing that concerns me is what happens to the DCR & SCR when a 350 crank is put in the combo I have listed above. A SCR of 10.4 seems a little high for today's gas and I have read that going above 8.4 on the DCR is a bad idea. Is a DCR of 8.6 that big of a deal? Is 10.4:1 ok with aluminum heads?

Using the Edelbrock Performer RPM cam in a 350 that is .030 over calculates out to a SCR of almost 10.4 but the DCR is 7.14. Is that better or worse then going over 8.4?

One last question - how important is it to keep quench below .040? Is it worth decking the block and/or changing pistons to get that number right on?

 

Think you're missing the point of Anne and Tom's comments...
If you put the 3.48" stroke crank in, you MUST get new pistons.

Stock deck height is 9.025".

327 crank == 3.25" stroke, 5.7" rods, pistons with 1.675" compression height
Top of piston at TDC is (3.25/2) + 5.7 + 1.675 == 9.000" or 0.025" DownInTheHole

350 crank == 3.48" stroke, 5.7" rods, pistons with 1.560" compression height
Top of piston at TDC is (3.48/2) + 5.7 + 1.560 == 9.00" or 0.025" DiTH.

if you try to use the 327 pistons with the 350 crank:
Top of piston at TDC is (3.48/2) + 5.7 + 1.675 == 9.115" or sticking out of the block 0.090". You're going to need some REAL thick head gaskets to make that work....

Sooo -- if you go the 350 route (or the 383 route) you'll need new pistons anyway.
If you're getting new pistons, you can get one with more dish than the 5cc (?) ones you have now. A 350 piston with an 11cc dish and your setup would give ~9.7 CR by my math.

If you have the budget for it, a 350 or 383 will play better with the auto trans and 3.42 rear gears, but figure you'll need to spring for crankshaft, pistons, balancing, machine work, etc.

The vooodoo is a pretty good cam, I definitely wouldn't swap it out for the Edelbrock RPM cam.

Which edelbrock heads do you have? What intake and carb?

 

I thought in 69 the 350 came out and the 327 was stoped I have a 68 large jounel 327 and thought it was last of the 327 ? mine is an HJ block

 

Harvey, the 327 block I have is not from a Camaro. The casting number indicates either a 302 4-bolt or 327 2-bolt and it is 2-bolt.

I have Performer RPM heads #60999 - 64cc chamber, 185cc intake and angle plugs and I have tried the Edelbrock Thunder AVS 650 and a Holley 3310 - 650 vacuum secondary. I am running an Edelbrock Performer RPM intake.

I realize I have to buy new pistons because I am going from a standard bore to .030 over. I am trying to decide weather to go with new 327 pistons (and rings) or spend a little more and buy a 350 rotating assembly. I think Pat Kelly's calculator takes all this into account when you put in the stroke, rod length, etc. and its kind of confusing when I read things that say stay below 8.4:1 DCR and quench from .025 to .038 or what ever, lol. Just trying to get it right since I'm going to be putting in all the work.

T, I like your idea of a 11cc dish piston if I go the 350 route. That seems to make the numbers work out pretty well. Thanks!

 

I have always loved the 327, the one I have now runs really well. Vortec heads, solid cam, 9.5 converter, 4.10 gears.

 

spend a little extra and build a 383. it really wakes the motor up. lots
more torque and that's what you want for the street.

 

Go 350 and check out speed pro H815ACP pistons. 12cc Dish with a 1.5/1.5/3.0mm ring pack. Cheap way to get a modern ring pack in an old engine. I just did one using a '69 350 block, Scat 9000 3.48 crank, and scat 3/8" capscrew rods. Worked out very well. Had it balanced, and bobweight ended up at 1822 g. CR is calculated at 9.6:1 with a total 0.045" deck, and 63 cc Vortec heads (measured).