bence13_33

A fellow forum member has a set of heads that he is willing to sell to me. I would like to hear what you guys think of these heads.

1969 Corvette 427/390HP Heads (Oval Port), Casting #3931063, Closed Chamber Heads

He says that they have stainless steel Manley oversized valves. My guess is they are either 2.19/2.25/2.30 Intakes with 1.88 Exhausts. The heads were recently cleaned up by a well-respected machine shop and are ready to be assembled. No port work has been done to the heads.

What is the going rate for a rebuilt set of heads like this? What are the combustion chamber sizes of these heads? Does anyone have any other information that might be useful about these heads?

I think the closed chambers will be good for my setup. I need at least a 10:1 compression ratio and in order to do that with open chamber heads, I'll need to run a domed style piston. I would then most likely run into piston to valve clearance issues with my cam of choice (Comp Cams 294 Solid Lifter Cam, .595" Lift). With the closed chamber heads I can accomplish the 10:1 compression ratio by running flattop pistons.

Flareside

According to "Chevy by the numbers", they're identical to the heads on my car (215). 100.967cc chambers and 2.06 intakes stock.

Be warned, my 427 is 10.25:1 with these heads, and it pings pretty badly on 94 octane. Your cam choice may barely let you get away with it, but you won't have much room for error.

LT1driver

If your pistons are open chambered you CAN NOT use a closed chamber head, pistons and valves will kiss each other badly.

Flareside

LT1, he said he'd run flat-tops with the closed chambers :confused:

BAD-L88

http://www.nastyz28.com/bbcmenu.html#heads

Above is a site you might find helpful for parts reference. According to the site the heads you ar elooking at are 100.9cc and were used on 390 HP and 400 HP 427's.

FWIW, There have been several aluminum heads for sale on Ebay lately.

mountainmotor

The big valves in those heads sre not really going to help w/o port work.Also some combustion chamber work needs done to unshroud the valves.Right at 50 hp can be gained by these mods.
You have the main ingredients,vette,4spd, gears and obviously money to create a street monster on pump gas.I would like to see you get some of the new Canfield aluminum heads ,put .250 longer rods in a 468 with a good cam and go!Nothing like the feel of all the low end your tires can take plus the motor getting on the pipe at about 4500 rpm!Kinda like a big orange 4 wheel Kawasaki! It is easy for me to spend your money though but planning the engine combination is 1/2 the fun.Hang in there.Do it once and do it right. .Edit to add the Canfields need some port work also.There are other heads that would work for you once you decide which direction you are headed.But 10.1 with that cam will not work with iron heads.


[Modified by mountainmotor, 5:13 AM 12/5/2001]

StrayDog

TO get 10 to 1 , you will need TRW 2300 f , DOMED pistons . which are the replacement for the 390 HP engine ...flat tops will result in 9 to 1 or slightly less.........the oval ports are a good set up with plenty of velocity up to 5500 or so....................wait thers more you can use closed chamber pistons in a open chamber head BUT NOT , open chamber pistons in a closed chamber head.......just my 2 cents but Edlebrock alum heads are a great price $1,500 completes & available 110 cc 0r 100 cc chambers that are semi open chambers & work with both types of pistons .......have a set on my big/block ......


[Modified by StrayDog, 8:34 AM 12/5/2001]

Flareside

Hey Bence, have you even checked out the http://www.chevelles.com board? These guys are great with big block performance questions. Have you seen their BSE combo? It's a recipe for a killer street engine VERY close to what you're doing. Look up Ed who goes by the handle "racer1320", he's the author/mad scientist responsible for it. There are a bunch of guys over there running this exact combo, and running mid 11's! This is by far the best bang for your buck.

Here it is:
"454+.060 = 467
-TRW # 2399 pistons with Speed Pro file fit rings
-10.0 - 10.7 CR depending on deck height, final combustion chamber volume and head gasket used.
-Clevite bearings - mains, rod and cam
-Fel-Pro gaskets
-GM 3/8" rods with ARP bolts and GM crank(cast is fine at this level) with ARP main studs and GM windage tray
-Moroso 6-Quart kicked-out pan # 20401 with pickup # 24440
-Melling oil pump
-Manley or DynaGear double roller timing chain
-#215 closed chamber oval port heads '67 - '68 with 2.19 / 1.88 valves, gasket matched and bowls blended
-Performer RPM Q-Jet Manifold with GM lifter valley splash shield
-Q-Jet carb with 75 main jet, 45B primary rod, AX secondary rods and B hanger
-1/2" phenolic 4-hole spacer
-GM carb heat shield
-Ultradyne 288 / 296 hydraulic cam with matching springs - double w/damper. cam specs are 231I / 239E duration @ .050 with .550 / .575 lift ground on a 110LSA. Install on a 108 intake centerline
-Rockers - either crane steel long slots or a roller. Isky are the best aluminum, Crower the best Stainless steel. Neither are needed at the power level.
-3/8" one piece pushrods Crane or Comp
-MSD ignition- 6AL box, coil and distributer(optional-allows easy curve adjustment)
-Headers - 1 3/4" PRIMARY TUBE WITH 3" collectors. Remove collector(cut off) and install(weld) Flowmaster Scavenger Collectors # C-134214300
-3" headpipes with 3" crossover and 2 1/2" tailpipes. All bends to be mandrel. Use Flowmaster Big Block mufflers 3" in and out, offset - offset (quietest performance muffler) or DynoMax Oval RaceMagnum.
-Mallory Comp 140 fuel pump, regulator and filter plumbed to stock 3/8" fuel line.
-Mobil 1 10W-30 oil, Ford type F trans fluid and Mobil 1 gear lube
-indexed spark plugs
With a turbo 400, ATI 10" converter, 3.73 gears and either slicks or DOT slicks this combo will run 11.60's to 11.90's depending on weather, tuning and driver. My best was 11.49 @ 115 in mine shaft air weighing 4000+ lbs. on pump gas.

This combo is fully streetable and was regularly driven to the track some 140 miles away and 2+ hours(one way) on a weekly basis. It was driven anywhere, never over heated and got 12-13 MPG on the highway with a lite foot.


Set the total timing to 36 degrees and shift at 5800 for best ET.

For my current combo just substitute a Comp cams street roller 238I / 244E duration @ .050, Performer RPM Air-Gap(not worth any ET), Holley 950 or 1000HP, 4.10 gear, lose the tailpipes and raise the shift point 200 RPM to 6000 and you'll run high 10's. Just don't forget things like a roll bar, SFI balancer, SFI bell housing shield, non-clip axles, and a real good suspension / tire package."

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[Modified by Flareside, 2:21 PM 12/5/2001]

Turbo-Jet

i'd say 2.190 on the intakes closed chamber heads might have more compression available, but there are issues with flame front travel, esp with a high dome. unshroading the valves is helpful, even if you lose a bit of compression. just make sure you check everything. did you see that post re compression vs hp?

bence13_33

Flareside:
I think I may try to pattern my engine after that one. 11.49 with a 4000lb car...yikes :eek: . That setup seems pretty sound, but I think I may choose to go with the Comp Cams 294 solid lifter cam instead of the suggested one. I guess I'll just save my money and get a nice set of heads...I may look into a set of Edelbrock aluminum heads. I'll stick with the oval port heads and 2.19/1.88 valves.

bence13_33

What do you guys think? Should I go for the heads and have them ported, polished and bowls blended or should I save and go for the Edelbrock oval port aluminum heads?

73 LS-4

Hey Bence, if you get rid of the 049 heads let me know, I've been looking for a set to play with.

:cheers:

Pat Kunz

69 N.O.X. RATT

Bence: The Edelbrock heads are a far better choise, if you can justify the costs. That is what it boils down to, will your budget allow for them.