Hello, I am planning to run a modified here in Ohio next year.

The track is Mansfield. 1/2 asphalt 8 degree banking. I am in quite a quandry about the internal parts that I should use. To run in the class, I need at least 550-600 HP. I plan to run a 383.

I have a desktop dyno but, I can't load all the info as I do not know all the specs for these parts. To follow is a list. I have been told that I should be able to get about 575 or so out of this. I got 583 with the limited specs I had on the dyno.

If anyone can offer some help here, I would appreciate it greatly.

Heads JEGS

555-51433
SB-Chevy High-Flow 220 Aluminum Cylinder Heads
2.10'' Int/1.60'' Exh Valves
1.550'' Springs,
.680'' Max Lift, Mechanical Roller
Assembled, Sold as Each


JEG'S Cylinder Head Specifications Part # 51433 23 degree valve angle, angle plug design, SB-Chevrolet
Materials

Casting: A356-A Virgin Grade, Heat Treated to T-6
Valve Guides: Manganese Bronze
Valve Seats: Alloy, For use with Unleaded Gasoline
Combustion Chamber: 64cc CNC-Profile Machined
Intake

Port Volume: 220cc
Valve Diameter: 2.100'' Stainless Steel # 555-20563
Valve Length: 4.960''
Valve Stem Diameter: 11/32''
Valve Stem Seal Diameter: .531'' Teflon
Port Dimension: 1.320'' x 2.190''
Flow: 310 cfm @ .700'' lift 28'' of water
Gasket: Fel-Pro # 375-1206 or Mr.Gasket # 720-5822
Exhaust

Valve Diameter: 1.600'' Stainless Steel, # 555-20565
Valve Length: 4.960''
Valve Stem Diameter: 11/32''
Valve Stem Seal Diameter: .531'', Teflon
Port Dimension: 1.530'' x 1.500''
Flow: 228cfm @ .700'' lift 28'' of water
Gasket: Fel-Pro # 375-1404 or Mr. Gasket # 720-5900
Valve Train

Stud Size: 7/16'', 7/16'' 14 x .875''(bottom) 7/16'' 20 x 1.950'' (top), # 555-20526
Guide Plates: JEG’S # 555-20520 (5/16'' pushrods)
Retainers: Chrome Moly Steel 10 degree, # 555-20531
Valve Locks: 10 degree
Pushrods: 5/16'' Heat Treated, Must Check Length
Springs: 1.550'' .680'' Maximum Lift, Roller Lifter, # 555-20541
Spring Cups: .570'' Inside Diameter Locater, .060'' thick # 555-20550
Accessories

Head Bolts: Stock Dimensions Recommend 12-Point Head
Head Studs: Stock Dimensions Recommend 12-Point Head
Spark Plug: 14mm 3/4'' reach 5/8'' Hex with Washer Seat
Stud Girdle: Stud Location Custom JEG'S # 555-20505
Rocker Arms (7/16''): Required Offset .150 Intake Left, Offset .150'' Intake Right;JEG'S # 555-20110: 1.5 full set; # 555-20115: 1.6 full set;# 555-20111 1.5 Intake Only Set; # 555-20116 1.6 Intake Only Set (4-.150'' offset left, 4-.150'' offset right)
Head Fastener Washers: Use Quality Hardened Washers
Accessory Bolt Locations: Stock Placement Torque Specifications
Rocker Studs: 45 ft/lbs.
Manifold Bolts: 35 ft/lbs.
Head Fasteners: See Manufacturers Specifications

Cam Comp Cams

12-922-9

Lift Int .660 with 1.5 rocker Ext .672 with 1.6 rocker

Duration @ 0.05 Int 264 Ext 268

Lobe sep is 106 centerline 102

Intake Hurricane from Midwest racing

Carb 850 cfm proform.

All roller lifters ( comp cams)and rockers (Jegs)

Pistons Weisco domes 13:1 +11cc dome

I plan to hold it together with a Eagle 4340 crank and scat rods. ( Because they are cheaper and rated to 600 hp)


This is in a 383 stroker 3.75 stroke 6.0 inch rods.

I am not sure if this combo will develop the needed hp.

I was told the the cam would work in as low as a 9:1 motor. rpm range of 3200-7200

I was also told that I would need to spin it at around 8000 for max power. As my intake runners are large as well as the intake valve at 2.10. It died on the dyno at 7200. And the hp started coming down.

Any help or advise would be a great help here. I do know that Midwest sells a motor for 6700. But, I want it to be my own and I want something different. I ffel that this setup could go well over 600HP tuned on the dyno.

Sorry for the long windedness here. Thanks to all who veiw and respond.

Have a great day.