dexleo2

Hello everyone,

I'm sorry because I know the 383 options have been beat to death on this bored, and I have been searching old threads and Have not found what I was looking for close but not quite. So with some reluctance I thought I would post what I have and what I'm looking for.

I have in my shop a 350 block a 010 block number (two piece rear main) with a scat strocker crank with 5.7 scat rods and flat top pistons. With a 64cc should be a 10.5:1 compresion ratio. The whole rotating assembly has been balanced. My question are this: what heads (64cc) would make the most sense with what cam shaft? Looking at flat tappet cam. The Motor will go into my 1985 Pontiac trans am and will be street machine and a drag racer. Give my your ideas of what would be the best top end combo for this. Power will be supplied to my borg warner 9 bolt thru a 700R4. Thank you in advance.....

Orr89RocZ

iTrader: (20)

What is your budget and what intake manifold are you running? EFI or carb? How fast you wanna go?

dexleo2

The car will be a carb. Would like to keep the price of the heads around or under a grand. Have not decided on a intake yet. I want to go as fast as the combo will go. I figure build the motor and then I will build the rest of the car around the motor.

Orr89RocZ

iTrader: (20)

Scat non forged assembly I wouldnt turn much more than 6200 rpms. For that, a cam around 230 deg at .050 is all it will need. If it has the scat rods with 7/16" bolts/capscrews then it should be good to 6500 occassionally. But still a 230 deg cam is all you need.

Something like a performer RPM air gap intake (dual plane manifold of your choice) will make power up to 6000-6500 which is perfect for your rpm range.

For heads, I'd run Jegs brand heads for around 1100 complete. These are same thing as Pro-filer heads which are GREAT heads at a great price. Or you can order them from Pro-filer dealers for about same price.

You will need aluminum heads for that 10.5 to 1 compression it will make with 64cc.

Cam can be just about anything but I'd like to see something like a comp xe274 cam or similar. 108-110 lsa with that carb and it should be ok. The Lunati voodoo cams are really nice too.
http://www.summitracing.com/parts/LUN-60104/

That be a nice cam although a tad bit bigger than the comp. Lift fits nicely with the heads just need to be sure the springs match.
This is next step down that would also be ok.
http://www.summitracing.com/parts/LUN-60103/

Anything in that range with good heads will do very well. I think my friend has a set of 200cc Brodix IK's with 64cc chamber. Nice heads that should work but would likely need a spring change since its set up for solid flat tappet I believe. Not sure of the spring rates but I think he'd take 1000 for them or perhaps abit less. Need to ask

Atilla the Fun

First, if you get the piston-to-head clearance around 0.040" where it should be, flattops and 64 cc will be nearer to 11:1. With a flat-tappet cam, no sense in looking at any heads other than GM Vortecs. Not that a flat is good for a stroker. How hard is it to find a roller block? Strokers get more benefit from the extra lift a roller can and should offer.

Orr89RocZ

iTrader: (20)

I agree roller is the way to go but if you already have the engine ready it's the cheapest option to go flat tappet. vortecs are great for mild builds but not enough for a 383 IMO and if it's flat top pistons then it's closer to 11 to 1 with 64cc heads and that with iron isn't gonna be happy on pump gas.

1gary

Orr-you could go with 72 cc iron heads and shave them to 67 cc.He needs to decide if he wants to fool with a gas additive or not.Also he needs to supply us with if the block was decked and if it is 0 deck or .010 down which both are kind of common.Once he has that he can then play with the SCR formula for head chamber size.

Oh yeah.Much in cam choices does depend on compression ratios.

Orr89RocZ

iTrader: (20)

yeah there are alot of variables left out and I've made some ASSumptions lol

Being street machine and drag racer...it sounds like a "max effort pump gas mill while being under a set budget and working with the bottom end that is limited in rpm"

Solid flat tappet may work too but for the sub 6500 rpm range, a good hydraulic with good springs should do it.

Atilla the Fun

Depends entirely on the cam specs.

Atilla the Fun

No point in investing in any heads "better" than stock Vortecs when they all have worse mixture motion, worse low-lift flow, worse port velocity, and need lots more lift to make up these shortcomings. Only with a roller cam can these other heads prove advantageous. 1.6:1 rockers won't get you there. Stock Vortecs aren't that bad for a 383. Not like you need a 180 cc head, that's enough port volume to get a 400 to make 525 HP with a too-small carb. But again, roller cam with over 0.540" lift using 1.5:1 rockers. You're chasing your tail to use this block for a 383. Sell it, the '87-up block is the cheapest way to get enough lift for a 383.

dexleo2

The block has not been decked... I do have some where in my shop a roller cam and retro roller lifters, and a set of sportsman 2 RHS heads. These are left over from my stock car days. The block is bored .040. Have to see if I can find that cam and lifters and get the lift and duration. Fooling with race fuel and addtives is nothing new for me.

92RS4US

I'd build the short block as is, get a set of good alum heads, the summit heads and the trick flow heads are done by brodix. If you can go roller do it, if not there are plenty of flat tappet cams that will give you good power like from Lunati. I'd go with the Edelbrock performer RPM air gap too.

1gary

I guess you have to be in the right mood to post a good reply.I like the RHS heads in general.The question of Vortec's VS aftermarket heads and which is better at a low lift,low RPM's is one as it stands right now in the mood I am in is one for another day.Suffice to say I don't agree with the analysis.

92RS4US

I agree as well just didn't want to get into a pissing match. Depending on the application for which a engine is to be used anything about stock will produce better results. For more power and performance you have to step outside the OEM stuff.