i'm building a '75 block 355, comp cam, edelbrock performer intake, dual 2.5" dynomax super turbo mufflers...it's an old autozone motor so it's probably a 8.5:1 motor

i have some 883 smogger heads on there right now. 78CC, 1.94/1.5.

my buddy will sell me his original '92 Z-28 TPI heads for $50. 58CC, 1.94/1.5. only drawback is having to modify my intake to fit straight studs. shouldn't be a problem though.

my question to everyone here is, is it worth it?! will these 3rd gen heads really boost my performance? are they worth $50? will there be any sealing issues with my intake if i modify the bolt holes to fit these heads?

another good question is, let's say i get these heads. well i believe the exhaust ports for these heads are considerably different from those of my 883s. so i'd need the flange for a '92 but the collector tube bends for a '79. do they make headers like this? or are the exhaust mounts the same so that i can use any pair that'll fit a '79 5.7L?


i'm a lil new to this building performance engines thing...especially tryin to do it incredibly cheap. be gentle and helpful please http://www.nastyz28.com/ubb/smile.gif

------------------
Click here, it'll explain it all (http://memimage.cardomain.net/member_images/1/web/265000-265999/265597_11_full.jpg)

buuuuuuuuuuuuuuuuuump

------------------
Click here, it'll explain it all (http://memimage.cardomain.net/member_images/1/web/265000-265999/265597_11_full.jpg)

If your buddy gives you the rockers and valve covers plus modify the intake it will work, I think exhaust port is the same except for on Corvette aluminum heads but your compression may be to high for pump gas.

blah
the heads are 993s
can anybody gimme info on these heads and if they're good for a street machine?

------------------
Click here, it'll explain it all (http://memimage.cardomain.net/member_images/1/web/265000-265999/265597_11_full.jpg)

993's are the second best smog head GM ever made IMO.
I'm running a set of GM Performance parts aftermarket 993 heads. They had almost $500 in work done to them after the guy bought them from GM. I have the flow numbers for them. They're ported pretty big and outflow many of the performance aftermarket heads out there.
The motor ran the dyno to 426hp and 417ftlbs.
Pretty darn good for a set of "smog" heads! http://www.nastyz28.com/ubb/wink.gif

haha
well i'm guessing these are aftermarket, crate motor heads considering this motor came from autozone

but they outflow cuz of all the work they had done :P so really, they're not longer smogger
haha

------------------
Click here, it'll explain it all (http://memimage.cardomain.net/member_images/1/web/265000-265999/265597_11_full.jpg)

Ha ha, yea, I guess you're right. LOL

<font face="Arial,Verdana" size="2">Originally posted by Eliminator SS:
Ha ha, yea, I guess you're right. LOL</font>

how can u tell the diff. b/t aftermarket and originals? also, is there any diff. in performance b/t the 2?

------------------
Click here, it'll explain it all (http://memimage.cardomain.net/member_images/1/web/265000-265999/265597_11_full.jpg)

The guy at mortec.com along with the seller of them told me that they were the Performance aftermarket ones.
I'm not fully aware of the difference though. I think it had something to do with more exhaust flow.
Like you said though, makes little difference now.

Mine are also the mexican heads. The mexican heads are the aftermarket ones, but I'm unsure how you tell which is the performance head and which came on a crate motor.

Super chevy or Hot rod magazine did an article about an engine that used these heads. I'll have to look it up though.

[This message has been edited by Eliminator SS (edited June 19, 2005).]

There are no performance 993s from the factory. CHP did an article on the Goodwrench crate engine where they ported the heads,back cut exhaust valves, milled the heads -3cc, used a .015 head gasket and picked up 20 hp or so.

unfortunately, i can't afford all that work http://www.nastyz28.com/ubb/frown.gif

------------------
Click here, it'll explain it all (http://memimage.cardomain.net/member_images/1/web/265000-265999/265597_11_full.jpg)

<font face="Arial,Verdana" size="2">Originally posted by nova77x:
There are no performance 993s from the factory. CHP did an article on the Goodwrench crate engine where they ported the heads,back cut exhaust valves, milled the heads -3cc, used a .015 head gasket and picked up 20 hp or so. </font>

but thx for informing me that all that stuff would seem to be pointless
i don't need evil street machine heads, just ones that are capable of putting 300hp to the wheels with little to no trouble

------------------
Click here, it'll explain it all (http://memimage.cardomain.net/member_images/1/web/265000-265999/265597_11_full.jpg)

The TPI heads are good heads, but which ones do you have? Theres the 081 castings (for 305s) that had 58cc chambers, and theres the 083 castings (for 350s) that had 64cc chambers and slightly bigger valves.

Either would be a nice boost in performance, but the 081s might bump the CR up a little too much.

actually, i dunno which casting they are yet...i'm still trying to get up w/ the guy

if they're 083s, i'll probably sell 'em to 1978LT
if they're 081s, i'll probably pass 'em up

i've got my heart set on vortecs now http://www.nastyz28.com/ubb/smile.gif

------------------
Click here, it'll explain it all (http://memimage.cardomain.net/member_images/1/web/265000-265999/265597_11_full.jpg)