[vinniekq2]

L69 my car is kinda like yours.Its a corvette so it handles ,,,,,fair (1981) Power? too much,,, purpose,knock over pylons in parking lot gymkahana races, sounds awesome, fuseable link? street tires, fun to drive 10/10,,curb appeal very good, chick magnet,,,rofl,,0/10

[L695speed]

Originally Posted by vinniekq2

L69 my car is kinda like yours.Its a corvette so it handles ,,,,,fair (1981) Power? too much,,, purpose,knock over pylons in parking lot gymkahana races, sounds awesome, fuseable link? street tires, fun to drive 10/10,,curb appeal very good, chick magnet,,,rofl,,0/10

LOL sounds like a sweet ride. I was gunning for the stock look restomod style. Looks bone stock to the untrained eye, but to those who know what they're looking at they know something is up. I even picked the wheels on that stock appearance mandate.

Anyone have any thoughts on these heads?
Scoggin Dickey Parts Center SD8060RA2 - SB Chevrolet Vortec Cylinder Head w/ 0.600 Springs for Roller Cams | SDParts - 1-800-456-0211

I looked at the BowTie ones F-Bird suggested. Talked to the machinist, he said for what I want it would be close, said get the Scoggin heads, and agreed with the XE282HR cam. Said that would be a nice sweet motor making somewhere in the power range I want. My friend who has Vortecs on his 82 TA was gunning for 500 horses and came up a bit short, but is very happy with it. I am gunning for 450, if I come up a lil short I probably won't care.

BTW for those looking at the summit block for a stroker build. I can get the block prepared including a tank cleaning with plugs, cam bearings boring 30 over for 460 bucks. Bought the engine for 250, and don't need to buy any stupid bits and pieces as I already have them. Assuming I sell the heads for 150 I effectively have a block with all the bits like the oil pan and machined for 383 for 550 bucks.

[F-BIRD'88]

The L-31 Vortec heads you get now are from Mexico and not near as good as the 96-2000 Made in Canada production L-31 062 vortecs
or the Bowties. You will come up way short on power without extensive porting on these recent heads.

They are not even close. The ports are crap on the new L-31 castings. Do it right the first time.

If you want handling get aluminum heads. Takes weight right off the front end of the car.
More than worth the little extra cost. Summit Racing 200cc street strip aluminum heads are a steal. Under $1K Big power too.

You cannot save you way to 450HP

[L695speed]

I'm not trying to save that much, I knew realistically it would cost me around 3 grand at least to build the motor (if I did the assembly myself). I just happened to remember the Scoggin heads and thought I'd ask about them. Also based on my friend's specs I'm close to what he has for a cam head combo. Its a question of details really, I'm going to put up the 906 castings for sale, but I'm not sure if I really want to go aluminum here. Cost skyrockets there, especially when I can get heads that would work just as well for the power I want for less. Even that stroker build website with all the combos had combos close to what I've listed and made what I want or more using L31 heads that were worked over and a smaller cam. I figured if I got a motor to start with, I would only need pistons, a crank, cam, heads, and if I chose to do so, roller lifers. Intake and Carb. Along with gaskets and headers. Problem I have with aluminum heads is the price. And frankly, I know from experience, the Koni Yellows I have upfront make the added wight a question of what weight?

Part of it is, this project has been going on for a couple years now, and if I go way overkill on the engine pricewise, it will just take longer to finish it. If I come up short of 450 horses and turns out I have 425 then so be it, my friend came up about 25 short of his 500 horse goal.

[vinniekq2]

I need to beak in again. the weight savings for aluminum heads on a small block is not that much.BUT,,, its not the shocks and springs alone that are affected by weight. braking is also a consideration. A couple hundred pounds total weight savings makes a big difference to everything,handling,braking,acceleration,,,
450 horse power is not a big deal,,,heads that flow 250 plus cfm and a cam/manifolds/and intake/carb,will get you there.
save weight,make power,spin tires,

[F-BIRD'88]

You are hell bent on building a expensive lame 383 that won;t make 450hp that will cost way more
than a dirt simple cheaper 355 that will make 450+hp.
Spend the money on heads. build a simple 30 over 350 (O decked) with flat top pistons and 64cc 200cc port heads.

10.5:1 cr

Brodix IK200
Comp XR280R-10 cam and kit K12-771-8
Set the lash cold at .012" .014" on this cam. 1.5" or 1.6 Summit/Scorpion roller rockers.
once a year

Performer RPM 750DP carb.
You have a 5speed trans. Make use of it.
This 355 engine will make 450+ hp and GLH for less money.

Use long tube headers and 2.5" Y ed into a 3.5" exhaust w 3.5" in out transverse mounted magnaflow muffler .
The Y pipe is flowmaster #Y250350
This 355cid combo will outperform your lame 383 plans.

[L695speed]

If I still had the five speed the motor would destroy it. The user refers to my original driveline. There is a T56 6 speed in there now. Everyone I've talked to say for a street car the 383 is the better build. Get more low down torque and its not as high strung as the 350 or 355. What is so wrong with a 450 horse 383? Thats considered a medium build that is loads of fun on the street. I'm not after the ten second quarter mile. Even the machinist said that it would be a nice motor. I already need to rebuild this motor, so why not stroke it out? I see no shortage of guys running Vortec heads on 4-500 horse motors.

The only thing I'd save on running the 355 would be the crank cost. As I would be able to reuse the factory crank if its viable. If the Vortecs are so bad on the street why are they so popular for builds like what I have? Sure I'm leaving performance on the table, but why go further when on paper that power figure will get me in line with several modern sportscars in the quarter?

[L695speed]

So you're telling me these....would be better?

Dart 127322 - Dart SHP Special High Performance Cylinder Heads - Overview - SummitRacing.com

[Cridder]

Originally Posted by L695speed

XE282HR camshaft at .510/.520 lift and duration of 230/236 at .050 lift. The block bored .030 over, factory 5.7 rods to save the money, along with Sealed Power speedpro flat top with 4 valve relief pistons with a Eagle aftermarket 3.75 inch stroke crank. rod length is said to be 5.7 with that crank, says external balanced. The balancer is the stock 8 inch one which I could have checked at the machine shop to be sure its balanced right. Compression would be at 9.7 with 64cc chambers.

Domed pistons would send the piston into the heads from what I read, unless they're inverted (dished).

9.7 is way under for a flat top, my 383 vortec is at 9.73 and that is with KB 18cc D-Dish pistons., i use a camaro flywheel, it has a lot of metal drilled out a one side to balance and i use a 400 8" balancer. i use the 270 magnum cam and gear drive, It pulls like a mule, you,ll need a good clutch when the 4 barrels hit. Pay the extra 50 or 75 bucks and have the 5 angle cut in on the heads, i dont know what that cam will be like clearing the rod shoulders but i had 2 that hit and 2 that were close.

[cdminter59]

No, F-BIRD'88 said these heads Brodix IK200. See post #21.

[Cridder]

Originally Posted by F-BIRD'88

You are hell bent on building a expensive lame 383 that won;t make 450hp that will cost way more
than a dirt simple cheaper 355 that will make 450+hp.
Spend the money on heads. build a simple 30 over 350 (O decked) with flat top pistons and 64cc 200cc port heads.

This 355cid combo will outperform your lame 383 plans.

I didn't know there could be such a thing as a lame 383, a Vortec one at that!!

Personally i don't see how a 383 can be built that isn't a stump puller, the short block should be built by someone with a bit of experience but other than that it's pretty strait forward, it's a bit more money but well worth the investment, I can't imagine anybody who's ever driven a 383 ever wanting to promote a 355!!!