Heus

I have purchased a short block 357 from ATK Performance. It is a roller cam block 96-01 Vortec with flat top hyper. pistons. I will be going with 64cc 2.20/1.60 heads from either Promaxx (2169) or ATK. Will be in the high 9's for compression. Looking for a cam to get me to 350HP/400TQ. The roller cam they use for that particular 350/400 crate engine is a .495/.502 roller with 220/224 duration @.50 and 112 LSA. I am thinking about the stock ZZ4 cam or the GM Hot cam which is .492/.492. Any thoughts? Torque is way more important to me than top end hp.

Here are the specs:
Block: Seasoned OE 4 Bolt Main 1pc Seal Roller Block P/S Dipstick
Bore/Stroke: 4.040 x 3.480
Displacement: 350 C.I.D.
Crankshaft: OE Cast Crank 3.480" Stroke Externally Balanced Rear/Internal Front 1pc.
Connecting Rods: OE Powder Metal 5.700" Stock Bolts
Pistons: Hypereutectic +6.9cc Flat Top
Piston Rings: Moly Rings
Compression Ratio: 64cc=9.9:1/72cc=9.1:1/75cc=8.8:1
Camshaft Bearings: Installed & Clocked to OEM Position
Freeze Plugs: Brass Installed & Sealed
Oil Galley Plugs: Installed & Sealed
Weight:285

StraubTech

The the ProMaxx heads and this cam it makes 415HP/420#ft

.510/.510
280/294
221/235
104/112
108

hugie82

the tight LSA 108 will give you max torque in a narrow rpm range but it will be an all around good runner.
I'm not familiar with Promaxx but what lift are they limiting their vortec heads at?

StraubTech

Power will be within 7% of peak torque for 2000 rpm. Within 10% for 2400 rpm. I don't feel that is narrow.

Karsten

I bought the HP89 350/375 HP Vortec with the following specs.

Horsepower: 375
Torque: 400 lb/ft
Block: Seasoned OE 4 Bolt Main 1pc Seal Roller Block P/S Dipstick
Bore/Stroke: 4.040 x 3.480
Displacement: 350 C.I.D.
Crankshaft: OE Cast Crank 3.480" Stroke Externally Balanced Rear/Internal Front 1pc.
Connecting Rods: OE Powder Metal 5.700" Stock Bolts
Pistons: Hypereutectic Flat Top
Piston Rings: Moly Rings
Compression Ratio: 10.1:1 Compression
Camshaft: Hydraulic Roller
Camshaft Specifications: 220/224 @050 .528in/.536ex 112LSA
Camshaft Bearings: Installed & Clocked to OEM Position
Cylinder Heads: Pro-Filer Aluminum 64cc/195cc 2.02/1.60
Freeze Plugs: Brass Installed & Sealed
Rocker Arms: Stamped Steel 1.6 Ratio
Oil Galley Plugs: Installed & Sealed
Oil Pan: OE 5qt.
Weight:350

If you are running an Auto Trans don't forget about a stall converter.

Karsten

Heus

.600 lift here's a link:http://shop.whiteperformance.com/PRO...MX9200-274.htm

StraubTech

I would have ProMaxx set the heads up not Whites.

76strokervette

Chris I have seen the pro-filer video on youtube for the 406,what did it make?

StraubTech

Which video sir?

76strokervette

Video is labeled 406 sbc with pro-filer heads from straub technologies made about a month ago.Clip shows 15 second dyno pull.

StraubTech

.285/293 @ .006
.231/.239 @ .050
.151/.152 @ .200
.576/.545 lift (with 1.6 rockers)
107 lsa

AED 950 (820) carb
9.9-1 compression
89 octane
HVH spacer
ported rpm intake with divider cut down
headers, probably some kinda 1.75" dyno headers,
6000rpm max

StraubTech

512HP at 6000 rpm
535#/ft at 4000