[calxen61]

I have a set of heads off 1973 454 with 113 cc and 2.06/1.72 valves( heads rebuilt). I have a 427 I plan to rebuild. Can I incorporate these heads in the rebuild or is the compression loss too great to overcome.

I want a moderate street engine.

thanks

cal

 

[chrisstandring]

They may foul on closed chamber domed pistons. That'll be your biggest worry.

 

[RB69SS396Conv]

Very easy to overcome that loss.

Don't build a 427 in the first place.

Kinda .... nonsense .... to spend extra money to build a lesser motor than you could with THE SAME $$$.

 

[calxen61]

Very easy to overcome that loss.

Don't build a 427 in the first place.

Kinda .... nonsense .... to spend extra money to build a lesser motor than you could with THE SAME $$$.

I have both the 427 and the heads so if they could work together than why not?
cal

 

[gnicholson]

open chamber heads work just fine with closed chamber pistons its the other way that causes problems.sometime in the 70's ls6 crate engines started coming with open chamber heads with the original closed chamber pistons and were rated at 10.25 to 1 compared to the earlier 11 to one.if you run the original 427 style 11 to 1 or 10.25 pistons you should be ok.figure on atleast a half point drop depending on the head volume.flat tops will put you in the low 8's

 

[VinceS427bb]

what pistons are you planing on using?

 

[calxen61]

what pistons are you planing on using?

Planning on using what this forums recommends. With the 113 cc heads I imaging a domed piston.

 

[gnicholson]

how much compression do you want? if you have a 73 049 head they are between 118 and 122 cc's usually unless someone has milled them a bunch

 

[calxen61]

how much compression do you want? if you have a 73 049 head they are between 118 and 122 cc's usually unless someone has milled them a bunch

These are 113cc. 2.06/1.72 valves

 

[gnicholson]

my next question is how do you know?did you cc the chambers?whats the casting # if the are the original 73 454 heads and havent been milled they should be what i posted

 

[calxen61]

my next question is how do you know?did you cc the chambers?whats the casting # if the are the original 73 454 heads and havent been milled they should be what i posted

I ran the numbers, the are from a 73 corvette

 

[calxen61]

I ran the numbers, the are from a 73 corvette

Cast#353049

 

[gnicholson]

049 heads are typically listed at 119 cc's. they are a good budget performance head and respond favorably to 2.19 and 1.88 valves and bowl work. if you use a factory type l36 piston you should have about 9.5 to one.about right for a good street performance motor.the l72 would be about 10to 1. plus there are all the aftermarket piston companies like je,diamond etc

 

[calxen61]

That's good news, what about the crank. I have a 427 tall deck with a good forged crank if it fits, or the crank in the 9.8 block. That engine is a two bolt 1968 replacement motor.

 

[gnicholson]

the crank can be used.it will need to be balanced

 

[calxen61]

the crank can be used.it will need to be balanced

Which crank, the 427 tall deck, or the one from the 68 427. This sounds good so far, what about rods and a cam.

Thanks
Cal

 

[kettbo]

the factory rods are decent
the Truck rods, also called "thumb rods" are better
the dimple HiPerf rods are the best
all benefit from modern ARP bolts and a re-size (this goes hand-in-hand)

used the 427 FORGED crank, it needs to be rebalanced with the rest of your goodies
thousands of home brew 427s out there. L2268 pistons are heavy but darn near bullet proof. L2300 pistons have less dome but will make 9-9.5:1 no issue. Naturally other pistons are out there

'049' heads are nice, most measure 120cc, not 113...bad internet info often repeated. Big valves are not a necessity, ask GOTAGO,,,but you must massage the heads to get some extra flow

Cams, usage, gearing, expectations please. Budget for a roller cam? I'm going to change mine flat tappet cam in my Vette to the 502/502 HR (new thread today).

 

[calxen61]

Budget will handle a roller. The car will need a new rear end so any gear can be put in. No trans so I can use anyone, streetable on pump gas but as many HP as I can get. I am not real picky.

Thanks a bunch
Cal

 

[kettbo]

Cal,

Kevin R and Mark gotago Smith have healthy street strip 427s
FRYNTYR Darryl has made a few too

Give me all the car info..your intentions, perf goal, priorities, etc

 

[Schurkey]

open chamber heads work just fine with closed chamber pistons its the other way that causes problems.

Usually true. NOT always true. Some closed-chamber pistons will hit on some open-chamber heads.