Looking for advise on this rolling chassis project. We have an 84 Z28 with a 4:10 rear Gear. Flowmaster Exhaust and are going to re-do the interior later.

Here's what we are looking for engine advise on:
350 4 bolt Block Casting 3970010 honing done.
Pistons Stock Flat L3022F 4 valve relief (6cc) cleaned.
Chrome Molly new rings.
Crank 2.45" mains .001” Over Sealed Power (measured good).
Rods Stock Clevite Std 0.0015” Rod Clearances (measured good).
Heads casting 3927186 2.02” camel backs (into machinist).
Cylinder Head Volume: 62 cc (dressed twice now) Port/Pocket Polished.
Intake Corvette 458520 GM Alum Rochester Q Jet
Carb rebuilt Q Jet 17057213AWP Truck (may have to richen it up)
Crane Cams tappet 113971 248/260 duration, 400/427" lift (1.5 ratio)
Springs single/dampener Crane 99868 (modified stock) 125#seat
340# @1.200 (.480" max)

1) Can we look at 1.6 ratio rockers & measure the valve clearance?
2) With the screw studs/plates do we use hardened stock length pushrods?
3) Can we expect to use 87, 89, 93 octane pump gas? ( 9.9:1 compression)
4) Non- SAE oil and what weight? (Brad Penn high Zinc as Crane suggests)
5) Do we need break-in Brad Penn or GM EOS in the first mix?

We want to do this right and justice to breath correctly.
We are on a teenagers budget for a street car.
We really want this in the modified stock 300-350 Hp range

Suggestions? Thanks

 

Welcome to the forum!
Sounds like you got a good project going.
Best thing to do is post all this in the third gen section.
Goodluck!

 

Sounds like a nice platform to start with. With the addition of the 1.6 rockers you will only pick up .030 more lift. I would start with a cam like the Comp. EX-268 with a 1.5 rockers. You will have enough spring for this cam and it will be a lot better then the little stick your starting with. You will need hardened push rods for the guide plates. If you getting close to 9.9-1 compression then you would need to run 93 fuel. Check the deck hight of the pistons to the top of the block and use a head gasket that will get you around .040-.045 from the top if the piston to the head. Use a cam break in additive with any oil for the break in and then you will need to run a oil with the zinc additive or you could just run a 15w-40 oil made for the diesel trucks because they still have enough zinc, because most still have flat tappet cams. With that small of a cam you will be trying to make 300HP. Step up in the cam department and it will be a big plus in the HP departement. Call Comp. cams and get their suggested cam for your combination. Thats the best call you could make for you build. At a latter date if your budget lets you I would upgrade the intake and carb also. If funds are short then do this at a latter date.

 

hay dan welcome to the forum. went ahead and moved your thread to the third gen section. should get some more good comments here

 

Well the red Gen 3 in in the heated garage for floor pan welding, but

Back to the motor build... We have Stock 6271096 pistons (+11 cc dish) that were with 76cc heads at 8.45:1 comp in its truck life on this 4blt 350 sbc. Now the 2.02 heads with 62cc (casting 3927186) are going to cost lots with nine exh studs stripped and a clean up on a few screw-in studs. That is calculating to 9.36:1 compression. Remember it's a stock honed block, ridge reamed, plastigaged to "Production" specs on the rotating assy. Installed and waiting on these camel back heads. We opt'd to not machine with the little wear measured (+.001 mains & std rod bearings).

Edit : Yes GORN Rods & Bolts reconditioned.

The Crane Cams 113971 Grind H-248-2 in also waiting (mild Intake = .400”/248 Deg, Exhaust = 0.427”/260 Deg) With guide plates we need hardened rods.

Standard length on these 1.50 ratio rockers is 7.800" on Gen 1 SBC ?

Crane springs 99848-16 are .480" maximum recommended valve lift.
Seat pressure 114 lbs @1.700" , Opening pressure 340 lbs @ 1.200"
Coil bind is 1.153"

Can I go +.1 over to increase Crane Spring Pressures OR stay stock?

The Roller Chain is in, Miloden HV oil pump is in. Will use drill/pump up with GM EOS.

What weight of oil? (Brad Penn high Zinc)

What Octane of pump gas?

 

Did you upgrade the rod bolt? Stock GM rod bolts have a lot of variation in them and there is no way to test if you have good ones or bad ones. At 300 HP it does not really matter who's rod bolts you use just don't use the factory ones.

I like to get the rods checked for micro crack, resized and new bolts on every engine I build. I learned that the hard way in my younger years.