I am so torn with which heads to buy! I want a higher compression engine which makes me think I need aluminum. I am pondering vette aluminum ar Edelbrock Performer Centerbolt Heads. I could go with Vortec heads but already have an Edelbrock TPI base that will not fit. I am only looking for about 350 horse power. What should I do? and which cam will match nicely?

 

What cam are you running? If you already have a Edelbrock intake, you may want to contact them about heads and a camshaft. I Know they have dyno proven combos put together for carbed applictions. They may have something for the TPI. If not let us know about camshaft selection, or ask if you have not yet selected one. Both of the heads you stated are gonna give you close to or just above stock compression ratio. You will need to either use a thinner head gasket or have the head milled a little to gain some squeeze. More compression can be found in replacing pistons, but that can get expensive.

 

You could easily hit your goal of 350hp and then some.
By souping factory TPI heads. They will need some upgrading
like bigger valves and full porting, but fit your car and
will more than do the job.

May not be as sexy as a new set of aftermarket heads
but will get the job done quite nicely for a lot less.

The heads to start with have casting # ending in 081 or 083.
These are common late TPI heads.


Here is the flow numbers you should expect after thouroughly
porting these heads.
L98 cast heads 083
numbers are:
Lift Intake Exhaust
.1 63.8 41.4
.2 120.6 88.2
.3 178.9 124.1
.4 215.2 154.3
.5 240.1 171.8
.6 241 180

 

What exactly are you wanting the 350 horse power out of ?

I am running a set of 1972 " 993 " casting iron heads on my 350 with a .125 dome piston which has my compression at about 10.3 to 1 .. These heads have good flow potential even though they carry the smogger head logo... I did all the porting myself, If you have no clue in what your doing then before you start grinding study this sites info, buy every book you can get your hands on and do all the reading you can. You'll need good cutting bits, gringing stones, sanding rolls, a die grinder, drimel and more and lotsa free time. while your porting.. Port the heads, plentum, manifold, and runners. ( Assuming it's TPI ).. If I had it to do all over again I keep saying I'd buy heads instead...
I'd do it all over again. An engine is a big air pump.. It's all about how you can get the air/fuel and exhaust in and out with no restrictions or deflections in gross amounts. Small little tricks can make small diffrences that can add up...


My newest mods are just about to come on line.. The shop that balanced my motor screwed something up and I had to re do it and since I wanted it new.. I redid it all brand new all over again and it had less than 100 miles on it.. bummer but hey... Good time for the mods I didn't do before...

Sooo .. this time I took off the 083 heads in exchange for the 993's which lowered my comression to a decent 10.3 I hand ported the heads. plentum,runners and intake manifold. Added a 52 mm Holley throttle body. Installed 1.6 harland sharp roller rockers. SLP headers ( have the factory duel cats ).. built my own adjustable fuel regulator. modified the intake manifold bolt pattern so to fit correctly.. Next week it comes to life.

Hope it has some *****.....

 

You wouldn't happen to have some numbers on fully worked over 305 center-bolt heads ???

thx,
RP.

 

The 081 305 tpi heads have the same potential as the 083
350tpi heads with equal porting and valve size.
The ports are the same.

The tpi heads have a better combustion chamber and spark plug
placement for power than the old 993 "smogger" open chamber heads. The ports are about the same as cast.

 

So what about the 416 heads?

 

Whoa. Are you saying my factory 305 TPI heads can be made to flow 240cfm @ .500 lift ... like the L98 heads ???

L98 cast heads 083
numbers are:
Lift Intake Exhaust
.1 63.8 41.4
.2 120.6 88.2
.3 178.9 124.1
.4 215.2 154.3
.5 240.1 171.8
.6 241 180

That is some kind of flow. Similar to many after market heads costing $1000 or more. Any suggestion for shops who can this ?

thx,
RP.

 

The 416 heads have the same potential also.
The most recent set I ported and flowed
were 238 intake @28 and 189 ex.

You'd have to describe this porting a generous.
A little bowl blend (pocket port) ain't going to cut it here.

Keep in mind that your results may vary.
But the potential is there.

Anything around 225 will result in very good performance.

There are books you can buy by David Vizard and John Linkenfelter that describe what needs to be done.
Check your local speed shop.

 

I suppose there are some that will do this but for the large
part it's just not economically profitable for a shop to spend the time on a customer's stock 305 heads to get these flow numbers, for a price you're willing to pay. Generally they will do a simple bowl hog and pocket port for extra, during the valve job.
There are shops that prepair stock heads for NHRA Super Stock
Competition but We're talking large coin.
It's kind of something you'd want to do yourself, in your spare time, then take them in for a good valve job.

I do it for grins just to spit my friends that have way more money
to throw around on new $$$ stuff than I do.

Pisses 'em off when I take "piece o' junk" 305 heads out of the garbage and turn it into some thing that out flows their aftermarket stuff.

I have sold a few sets. But not much money in it.
A paper route would be more profitable.

You're much more likely to find this stuff for sale all ready done.
Wether they actually flow these kind of numbers will vary.