[machinestheman]

the engine is a early 70s 400 sbc 509 casting .30 over
with rhs 64cc vortec heads with 170cc runners
cam lifters rods pistons from a summit kit saying this engine should build 350-375 horsepower (with everything else stock)
cam has hydraulic lifters with roller rockers on top the heads
offenhauser intake i believe is a single plane
10.5-1 compression ratio

and looking to run nitrous does all this seem to be able to hold a 150 shot for weekly drag and occasional driving

also cfm carb should i use for this setup thinking with the nos a 750 or 800?

85 buick regal considerably stripped out is going to be the recipient

[DoubleVision]

What pistons? what rods?

[machinestheman]

the rods are aftermarket from summit but they are stock specs the pistons are hypertech domes

[DoubleVision]

You can contact various nitrous company`s that will tell you how high you can go. with a dome hyper piston on race fuel I wouldn`t go over a 100 horse shot. Make sure you have a top notch ignition system from the point of ignition to the plus. Nitrous hit`s the intake at minus 128 degrees so a hotter spark is recommended. You`ll also have to retard the timing slightly with nitrous use.

[red65novawagon]

For every 100hp start with 2 heat range colder plugs not hotter or you'll have detonation problems plus you'll need to go 2 degrees less timing and learn about reading the plugs, the nitrous directions should tell you this. It's wise to be conservative on your tune 1st time out.

[ap72]

domes? Reverse domes right? otherwise your compression is WAY too high. What are the cam specs? at 10.5:1 you're going to need a healthy sized cam. Heads are too small for that compression and displacement.

[machinestheman]

i found a set of afterburner headers that will fit in the cutlass any horror stories withese out their

[machinestheman]

oh and i also have the smaller 6 3/4 inch harmonic balancer should help twist it up a bit better

[406 bug]

Good luck.

[Chevrolet4x4s]

To go with the 6 3/4" balancer you will have to go with an internally balancerd flywheel/flexplate and crankshaft
Shane

[techinspector1]

Originally Posted by machinestheman

oh and i also have the smaller 6 3/4 inch harmonic balancer should help twist it up a bit better

Do you think maybe there's a reason the GM engineers used an 8" damper with the 3.750" stroke???? Do some research into harmonics.

[Chevrolet4x4s]

Originally Posted by techinspector1

Do you think maybe there's a reason the GM engineers used an 8" damper with the 3.750" stroke???? Do some research into harmonics.

Am I going to run into problems with harmonics in my vortec 406 ? Internaly balanced crank,Its at the machine shop now having the rotating assembly balanced .
Shane

[techinspector1]

Originally Posted by Chevrolet4x4s

Am I going to run into problems with harmonics in my vortec 406 ? Internaly balanced crank,Its at the machine shop now having the rotating assembly balanced .
Shane

Use an 8" neutral balance damper from a 350. Here's a rebuilt one for 33 bucks from Damper Doctor that uses a 2:00 O'Clock timing tab....
http://www.damperdoctor.com/Merchant...egory_Code=CHE
and here's the same thing for use with a 12:00 O'Clock timing tab......
http://www.damperdoctor.com/Merchant...egory_Code=CHE

Use a toothpick to apply yellow paint into the TDC groove on the outer damper ring so you can see it easily with a timing light.

[Chevrolet4x4s]

Thanks
Shane