miled 993 casting heads

jessie355

Daily Driver
Oct 23, 2008
21
0
0
Ringgold GA 30736
what about haveing the stock 350 heads that are 76 cc milled 10 thousants what would that bring my compretion too need some help please pistons are stock 350 dished 4 valve relief
 

cobalt327

Weekend Racer
Feb 11, 2010
56
0
0
Atlanta
jessie355 said:
what about haveing the stock 350 heads that are 76 cc milled 10 thousants what would that bring my compretion too need some help please pistons are stock 350 dished 4 valve relief
Milling your heads ten thou will decrease the chamber of a 76 cc SBC head by less than 2 cc. Or from 8.3 to 8.4.
 

jessie355

Daily Driver
Thread starter
Oct 23, 2008
21
0
0
Ringgold GA 30736
well ill start over have a 350 2 bolt main stock bore with stock pistons that have a dish with 4 valve reliefs and a stock aluminum intake with a 600 holley have headers with 2 3/4 in pipes with 2 chamber flows and a lunati bm2 cam 292 292 480 480 lift cam and a 350 turbo trans what kinda horse power u think ill get out of this set up with the 58cc ho 305 heads that have the straight down center intake bolts the stock 350 heads993s and the 882 with 202 160 valves
 

cobalt327

Weekend Racer
Feb 11, 2010
56
0
0
Atlanta
To start with Jess, I'll try to answer the PM:
jessie355 said:
882 are all stock i was thinkin of getting the stock 350 heads that are993 i do believe miled down 10 thousands
So none of these heads are 2.02's?

Those 882/993-type heads are "smog" era castings, and do not flow well.

The 416 casting number 305 heads have issues as well, namely smaller 1.84" intakes and smaller ports than the 350-type heads. There are exceptions to this (as there is nearly everything auto-related)- there are "swirl port" heads used on the TBI engines that don't flow much further up the rev range than stock 305 c/n 416 heads do, but they make a lot of torque- they were truck heads, after all.

The 416's will raise the CR , and flow just 'alright'- and this is if they have 1.84" valves and not the 1.72" :evil: valves. However, they can be made to flow decently w/some hand blending and port work. But if you don't know how or lack the tools, this isn't an option.

These days, the hot set-up for iron factory heads, are the Vortec used on the L31 truck engines from '96-'02. They came on truck engines, but flow great.

Edelbrock and others make the intake manifold to fit them- stock was EFI. And the old intakes don't fit.

If it were me, I'd try to sell all those heads and use the money to get the Vortecs.
jessie355 said:
well ill start over have a 350 2 bolt main stock bore with stock pistons that have a dish with 4 valve reliefs and a stock aluminum intake with a 600 holley have headers with 2 3/4 in pipes with 2 chamber flows and a lunati bm2 cam 292 292 480 480 lift cam and a 350 turbo trans what kinda horse power u think ill get out of this set up with the 58cc ho 305 heads that have the straight down center intake bolts the stock 350 heads993s and the 882 with 202 160 valves
Your pistons could have anything from .060" to 0.100" dish, IIRC. You don't know what the piston to deck measurement is, nor the exact chamber sizes of the heads, so guessing the CR is a crap shoot. I'd guess about 8.4 for the 882/993 heads, and maybe as much as 9.8 w/the305 heads depending on the cast number.

Using the OEM Q-jet intake w/an adapter to use a square bore Holley is a poor set-up. I'd run a Q-jet, but that's me. You need a square bore intake if you want to use the Holley.

As for HP, I wouldn't have any idea. Maybe someone w/a calculator could run the numbers for you.

One last word: Vortecs.
 

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