i abandon my search a few years ago when i bought the house, im starting to look around again, i have a 91 firebird, 305 tbi..................ill be using an slp 51002 cam, gross lift is .480 in .487 ex..................i want to go aluminum but if there is nothing i can use then of course i wont be able to....................i thought for sure the edelbrock e-tec 170 would work, i just got an email from tech saying they wont and they offer nothing for a 305, i know afr used to but dont anymore.....................help me narrow this down, thanx

 

350 heads bolt right on

but why are you spending so much money on a 305?

 

i knew that was coming, ive done so much work to this car ,all i have left is cam and heads, and intake depending on head....................my next car is a z06, so for now this is it.........................you say 350 heads will bolt on, why did edelbrock say none of their heads will work?


Sorry none of our heads will work with your cam.

For all replies please include the ORIGINAL Email.

Thanks - Gregg Suyenaga, Edelbrock Tech Dept.

-----Original Message-----
From: wasp [mailto:wasp9166@yahoo.com]
Sent: Monday, May 29, 2006 2:02 PM
To: edelbrock
Subject: head for 305?


do you guys offer an aluminum head for a chevy 305? gross valve lift on cam would be .480 in .487 ex........................would the e-tec 170 work

 

Trickflow makes a great head for the 305.

 

I know 350 heads will bolt right on because I've done it before


But I'll never modify a 305 as long as I live again

 

350 heads will work, but the valve size will be the limiting factor. Anything with 1.94/1.50 valves should work. I'm pretty sure that's what the World Products S/R Torquer's use. Been a long time since I looked at those heads.

 

There is exactly ONE aftermarket head for the little 305 that I'm aware of, and it's not exactly super high performance..... World S/R Torquer 305s. Cast iron, 1.94/1.50 valves, rather old-school ports and chambers. Nothing to write home about.

Stock 350 heads with 1.94/1.50 valves will bolt on but watch out- they often have significantly larger combustions chambers than your 305 heads (~58cc) and will tank compression pretty badly on a little 305.

Many guys have successfully used Vortec heads on a 305, however. 1.94/1.50 valves are certainly about the limit on the little bore 305 and that's what a stock Vortec head has. The Vortec combustion chamber is actually about 62cc right out of the box (despite the fact they are spec'ed at 64cc), which isn't much bigger than your stock 305 heads, so compression stays about the same. Of course, you have to have a matching Vortec intake and get the "modified" ones that can take more than .470" lift, like the stock ones do (Scoggin Dickey modified Vortecs, for instance).

Also, a set of ZZ-4 heads (aluminum) will also bolt on, have the exact same sized chambers as your stock 305 heads and appropriate 1.94/1.50 valves and will take an early-style intake bolt pattern. However, they don't really flow very well by today's standards and aren't really the latest generation of port/chamber design. They are aluminum, however, and will shave about 50 lbs. off the nose of your car. Not sure if they'll take as much lift as you plan on giving them or not- I haven't owned a set a many years.

 

so scoggin dickey vortecs or zz-4 ? the vortecs arent aluminum huh? who makes zz-4? i remember from my discussions years ago trick flows arent that great and neither are the worlds..................comparing these four tho i would think one would be the best of all? i also remember the 58cc chambers and valve sizes, so i doubt any 350 head is for me...............refresher here, what does scoggin do to the head to allow it to work with greater than .470 lift?

 

Trickflow makes a 175cc head specifically designed for small bore SBC engines like the 265, 307, and 305. It is an aluminum head, 56cc chambers, 1.94/1.50 valves, and its a great head! Flows near what their 195cc KD heads do.

The only other real option for an aluminum headed 305 is to use the Corvette L98 heads. They have 58cc chambers, 1.94/1.50 valves, but they really don't flow worth $hit unless you do some heavy port work. They are actually one of the worst flowing heads GM made untill you open up the ports some.

 

I have a set of 113 aluminum vette heads I was going to use on my 305tpi but never have. It runs so good and smooth like it is, I'm afraid if I change cam and heads, it will run like crap. I'd probably sell them though.

 

Air Adam has a good point- I forgot about the Trick Flows for the 305. That makes TWO aftermarket heads for the little 305!

ZZ4s are GM heads- they come on the ZZ-4 crate motor and originally on Corvette L-98 TPI engines.

Chances are the Trick FLows are your best bet for power, although I wouldn't sell the Vortecs short. Lots of guys making impressive power with them. It's just the PITA of dealing with their different intake pattern and needing modified versions to handle any kind of semi-serious cam.

 

so the trick flows i wouldnt need a special intake then? im using an edelbrock tbi now........................these heads must be somewhat new, i dont remember reading about them, i plan on reusing the lifters since they are roller, what about the pushrods? should i step those up and would the length be the same with this cam?

 

I've got about 4 sets of heads I will be selling to get those aluminum trickflows.I can't help it I'm sold on them.

 

Yeah those trick flows look really good. And they flow enough + have enough material for porting to support a 350 or bigger later. Can't really go wrong with them.

 

pushrods anyone? and just out of curiosity, what is the lift on the stock cam?

 

bueller?

 

.450"- .480"

 

the stock cam is .450 intake and .480 exhaust? this cam is a bit different on the intake if thats the case,.480, but almost the same on exhaust ,.487, unless .007 is alot.............................im also looking to get aluminum valve covers, i was browsing summit and see most centerbolt covers have a grommet each, drivers is pcv and pass is breather.................i dont see any with oil fill cap?

 

no, the stock cam for a tbi is like .39x or .40x

i'm running the 113 heads with a bit more cam then you and a bit more compression. i'm running the car tonight, i'll see what she does then.
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i don't fully agree with this statement. i had them on my 360 and went 12.16@110mph peddlin' it out of the hole so as to not light the tires up. now i've done a little work to them, but only a mild bowl blend.

these heads feel pretty strong on my 305 too.

 

whats the lift on the cam your using? this slp 51002 is a bit older, ive had it on a shelf in my garage (ahhh, the old days when i could spend all my money on car parts instead or mortgage and taxes =( )....................at that time i remember slp telling me you couldnt go too big on the lift on a tbi, something about the computer being confused by vacuum? now im wondering if i should sell this cam and get an up to date one

btw, i also have 3.73 s , precision with aburn diff from reider racing

oh, i see now you have a camaro, not tbi?

 

huh, called slp, he said if i were to go any bigger on lift id lose low end .......they dont even offer anything for these anymore, everything is ls1 or ls2............................click 82-92 f body on their site and they have rocker arms and springs ,lol

 

max lift for the 187 heads ranges from .450 to .480. Check out the Cam sticky in the TBI forum.

 

im not sure i follow you? 187 heads? trick flow offers springs up to .600 lift...........anyways im .487 max so im ok

 

mine has a holley on top. cam specs are pretty stout .480"/.500" 238*/248* @.050

187 heads are the tbi 305 heads. stock, they are limited to a cam that has .450" lift or less cause you'll smack the retainer if it's not milled down to
run a bigger cam.

the tbi can handle bigger stuff, but you'll need some serious chip tuning once you get into doing cam and heads. go spend some time on the tbi board and see what's needed to run bigger cam and heads.

 

im actually looking into that now, pocket programmer some eproms etc...........im gonna dial in burning eproms on the motor now then do the cam and heads, makes sense to me