1970 383, 4spd, 355 gear engine planning

[Gunner75]

Getting ready to order parts for my dads car. Curious on thoughts for this engine build.

1970 383 bored .030" over
Stock crank and rods
Coated pistions, maybe forged.
9.5:1 compression
Stock 906 heads
4 speed car

Looking to run one of two cam packages:
Comp Cams Kit:
21-222-4 with XE262H grind
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=706&sb=0

or

21-223-4 with XE268H grind (Slightly rough idle)
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=707&sb=0


Also looking at running the Comp Cams Ultra Pro Magnum Shaft Mount Adjustable Rocker Arms and measured pushrods once length is acquired.
http://www.compperformancegroupstor...tore_Code=CC&Screen=PROD&Product_Code=1621-16

I will likely be topping it off with the factory cast intake and Holley 600CFM factory replacement carb I picked up for the car (only factory item the car is missing). Have a couple 750's laying around as well.

 

[Derwud]

I would go with the 268 as the 262 is a step down from stock (If memory serves me). Don't bother with the roller rockers for now, save it for a more modified engine. As for carb, what do you want to do with the car..

 

[Banzaiii67]

Seems like you and pop's would be happier with an aluminium intake and a bigger carb, not sure what the thought is there. Also with 383 the piston selection is tricky, you'll want to deck your block to get the piston up in the hole to achieve anything more than 9:1 compression.

If you weren't going to change a thing and assuming your using exhaust manifolds, I would go with a cam on a 112-114 Lobe Separation. The small summit cam K6400 would be a good choice and priced right. Crower also has several on 112 LS that would work pretty well with that combo #32916 or 32241.

Here's that summit cam
http://www.summitracing.com/parts/sum-k6400

and here's the cam card for it.
http://static.summitracing.com/global/images/instructions/sum-6400 cam card.pdf

 

[66Satellite47]

With the stock 906 heads, be sure you know what the actual CC's are, they vary quite a bit. You need to check all the dimensions to know what the compression really is.

 

[GetX'd]

Whichever you do gonna be a sweet build. Welcome to FBBO. As you can see you're already getting some good advice. I have a similar build under a six pack and got some nice hp out of it on the dyno. Haven't had a chance to test it on the street yet.

 

[Seventy]

Like 66sat said, make sure you know which heads you have.

For that kind of motor I would look into the speed pro coated pistons, falcon sells them with rings for like $360 a set {clevite or hastings rings}.
Are you going to have this motor balanced? if not {usually costs around $300} I would weigh the stock pistons and buy the closest set you can get...

For the cam I like this one http://www.ebay.com/itm/Lunati-Vood...2LK-/390983276935?hash=item5b086b5987&vxp=mtr

For your intake I would spend the money and grab a used aluminum one from ebay or the forum and run a nice 750, carbs and intakes are very inexpensive and will make the biggest difference when it comes to reliability and head aches. My cousin spent all kinds of money building a sbc stroker engine for his nova, then threw the old dirty carb on it from the motor that came out, it ran terrible for 2 summers, and then finally he broke down and bought a new carb, he instantly admitted running that car for 2 years with that junk carb was one of the dumbest things he has ever done...

- - - Updated - - -

Like 66sat said, make sure you know which heads you have.

For that kind of motor I would look into the speed pro coated pistons, falcon sells them with rings for like $360 a set {clevite or hastings rings}.
Are you going to have this motor balanced? if not {usually costs around $300} I would weigh the stock pistons and buy the closest set you can get...

For the cam I like this one http://www.ebay.com/itm/Lunati-Vood...2LK-/390983276935?hash=item5b086b5987&vxp=mtr

For your intake I would spend the money and grab a used aluminum one from ebay or the forum and run a nice 750, carbs and intakes are very inexpensive and will make the biggest difference when it comes to reliability and head aches. My cousin spent all kinds of money building a sbc stroker engine for his nova, then threw the old dirty carb on it from the motor that came out, it ran terrible for 2 summers, and then finally he broke down and bought a new carb, he instantly admitted running that car for 2 years with that junk carb was one of the dumbest things he has ever done...

definitely call falcon and see what their best price is on all your parts like bearings, pistons, oil pumps, etc 601-693-8282 extenion 166

 

[Gunner75]

Carb and intake advise above is on par with what I am really leaning on. We have been flip flopping from "keeping it factory" or adding a few updated options such as carb, intake, headers, and a few other visible items.

My machinest is to check out the piston options that are not overkill. I believe he was also suggesting Speed-Pro Hypereutectic with coated skirt. We are to discuss this evening.

As far as the adjustable rockers, nearly everyone I spoke with prior to the advise above suggested running them. The ones I have need replaced regardless.

Car is weekend driver, fun car. No long hauls, but occasional 50 mile weekend trip (maybe more, maybe less).

I'll hit the books tonight and discuss the input above on head cc's, pistons, etc. Thanks fellas!

 

[kiwigtx]

I take it this is a 70 Roadrunner that the engine is for. Is the car an Air-Grabber equipped car? If so, then carefully consider any aftermarket intakes with height in mind. You need to make sure there is sufficient clearance so as not to interfere with the Air-Grabber box and baseplate when the hood is closed.

Here's a little piece I posted on the subject a while back.. There are more threads here regarding the same issues;

http://www.forbbodiesonly.com/moparforum/showthread.php?65535-Air-Grabber-baseplate-technology

:icon_thumright:

 

[Gunner75]