I have a 305 TBI RS and I was wondering if these heads would fit

http://www.jegs.com/i/GM+Performance...58060/10002/-1

Any other suggestions? FOR HEADS, keep the 350 suggestions to yourselves for now, I need something reasonable. Thanks in advance guys.

 

Should be a decent upgrade but you are going to need to do some spring work and minor valve train upgrades in the future for any kind of higher lift cam. I do beleive that you will be losing a little compression as well. I think that the 305 heads are 58cc chambers. But for a basic rebuild or upgrade they would be a good head to go with. Just my 2c's

 

You should be able to pick up a used set cheaper than that. When I got mine locally I pain $100 for a hydro-locked 350 with '062 vortec heads then paid $250 more for springs, guide plates, screw in studs and labor at the machine shop where I got it all installed, a 3 angle valve job, the needed work to allow .600 lift, and new seals, milled and hot tanked.

 

You will definitely need machine work with those heads. I had a set, and the max lift was .450" Over that, and the retainers would contact the seals. The stock valvetrain is only good for a stock cam with ~.400" of lift. You might be better off just getting bare heads and having them machined for screw-in studs and additional clearance. Also, the 64 CC comb. chamber will drop your CR a bit. Another option is to get a set of LB9 heads and port them and do the machining to those instead. Properly done, they can deliver flow close to the stock vortec heads.

 

Thanks alot for the advice guys, but do you think the loss of compression is worth it or would I be better off getting a specific but a bit more expensive head? like these? http://www.jegs.com/i/World+Products...42650/10002/-1

 

The S/R Torquer 305's are one of the few decent heads available for 305's.

My opinion is to save your money and not buy heads for your 305 TBI, yet. There are other, easier ways to upgrade the performance without tearing into the engine.

Have you done headers, exhaust, gears/posi, first?

 

Totally agree, do the bolt on's first. Once you've done all that and are ready to dig into the motor, go with a mild cam and Aluminum L98 Corvette heads. They are the best heads available for a 305 IMO. I ran them on my old 305 and they rocked. Car went mid 13s@101mph with a 2.2 60ft and a 3.23 gear. Only other mods were headers, ported intake, mild cam. STOCK TUNE.

P.S. L98 heads have no EGR provisions, so you'll have to eliminate the EGR and disable it in the chip, or run a corvette intake base and plumb it in from the headers.

 

For future reference.

Besides the L98 aluminum corvette heads, what other heads are there that are aluminum and will fit the 305 TBI, even if work is needed. I'd like to go away from the cast iron heads and save some weight. This is future reference only, I am in no shape to buy heads but would like to gather information on each aluminum head so when I do need them ill know anything and everything about what i will need and which will benefit me the most.

Thanks guys.

 

Vette L98 heads are the only AL heads with 58cc chambers that will retain the compression on a 305. ZZ4 heads are the same as L98 heads by the way.

 

NO! this is a 4 bolt head - per side and if you have a 1990 305 the intake will not bolt up.

 

Jeez, thanks, that clears up a lot, now I have to go back and read everything I have about the ZZ4 heads over again haha. Ill probably pick those up when they're needed. Thanks again.

P.S. Centerbolt as well?

NOTE: REALIZED THIS IS DIRECTED TOWARDS THE JEGS HEADS, but could you still verify this for me. Thanks.

I have an 89. Which uses a 6-bolt manifold. So the ZZ4 heads will work with my edelbrock 3706 performer manifold as well as my 2055 headers and Centerbolt valve covers?

 

The aluminum L98 '113 heads have the older style intake manifold bolt angles. No big deal, to use a stock TBI intake only need to slot the center 4 holes (2 on each side). Or better yet use a carb intake with an adapter plate.

See this thread for good information on the '113 heads:

https://www.thirdgen.org/forums/tbi/...num-heads.html

RBob.

 

anyone know how much these usually are used? and thanks alot for all the advice, yeah, i am going to all those "preliminaries" first, but i'm just planning out all that i want to do in the future.

 

Thanks, I guess you missed what I said. I AM using a carb intake with adapter, it will be the Edelbrock 3706 performer manifold. So everything should work fine then in the end.

P.S. might look into another manifold without EGR since the l98 heads just cant use the EGR.

Going to read, thanks again for the thread you posted.

 

That was a good read, Ill save that and read it again. Thanks. Can't wait for it to be time for a head/cam upgrade.

I'd like to get a new set if possible.
@ Rbob: Is this the correct part #12556463 for the ZZ4 heads brand new from GMPP. Thanks.

 

Yes it is.

RBob.

 

since you are the man on the topic rob - when you notch the tbi or tpi manifold, do you get some type plug to put in to make sure it is tight?
i am going to run some heads that are all 90 degrees but i am going to use my tpi which has 4 72 degree center bolts.
i was going to notch the manifold so it could fit the 90 degree ones, but is there a plug you can put in so that it is a good thight fit when you torgue the 4 center bolts down?
did i say that right?

 

the only problem i see with the zz4 heads is the smog ****'s here in cal. it will stick out like a sore thumb when they see you have an external bypass like the vett has.
someone on this board was going nuts trying to get past the smog ref because the vette used a different number for the egr and it needs an egr with heat if your original had the same thing.
its a kick in the head when you not only have to worry about if it will work, but now you need to worry about smog *****.
but H8 is not in cal so i dont know what they will do in ohio.

 

Ohio doesn't have strict emissions I don't think (my brother almost passed with blown valve seals), and are possibly getting rid of them completely in 2010. I don't plan to do heads and cam until my suspension is setup, which should take a couple years. I pretty much know just about everything I will be getting into for each part of the car, now I just need the money to do everything.

Might look into a second job if possible. Suspension gets expensive.

Thanks RBob.

 

I've fit a stock TBI intake to a set of '416 heads. To get the bolt heads to seat square with the intake I used some wedges. These were made from a piece of 3/4" (maybe 7/8" or 1"? I don't remember) aluminum round stock. Drilled a 7/16" hole down the center. Used a saw to cut 4 wedge shaped pieces.

Placed one on each bolt before threading them into place.

Can purchase what is known as "beam washers", which are wedge shaped or tapered. Others here on TGO have mentioned using old rocker arm pivots. With the round side toward the intake.

RBob.

 

The Corvette L98/ZZ4 heads are nice, but there's too many problems, in my opinion, to make them effective for a TBI setup. First is the different intake bolt angle, but that is solveable by grinding the center four bolt holes to match. Second is the missing front accessory bolt hole for a serpentine setup. That's solvable by drilling and tapping the hole in the correct spot. Third, and this one is not fixable with current technology, is the lack of EGR crossover passages in the heads to work with the TBI intake. The aftermarket TPI intake has the passage built in for the Corvettes, but the TBI intake does not. There is no way I know of to make the Corvette heads work with EGR and the TBI intake, so that takes them off the list of acceptable heads for an emissions application.

Doesnt Trick Flow or Edelbrock makes some 180cc aluminum heads with 58cc chambers?

 

By searching tgo it kind of seems like tese heads may be nice with some good valve springs, thought they are 175cc.
If skipping the many "wenn i was a virgin" post in this tread, there is some interesting information.

https://www.thirdgen.org/forums/tbi/...6cc-heads.html

 

dont know if anyone will see this one but i noticed that Kevin was talking about l98 head problems and he mentioned the serpentine belt not hooking up. will it hook up ok with 416 heads?
i have spent so much time looking at heads for the 305 that i completely missed even thinking about that.
anyone know?

 

1.) I plan to use the Edelbrock 3706 intake which should have the correct bolt angle correct? If not grinding can fix that. CHECK

2.) Which head would this be on or is it for both? I'm asking because in the future (Wynjammer S/C upgrade), I plan to completely remove my smog and AC pulleys. As the new SC kit will route the belt with its own idler pulley.

3.) If I plan to get rid of EGR from the computer and engine, I won't see any problems in the setup I am going with and with it working correctly?