92RedBird

What are the best heads for a 305 TBI.

lars92RS

I know you are new, but you have to do a search on that stuff before you ask such a basic question. this has been covered over and over agian. Just try doing little research on your own on this board then ask a specific question and you'll get a lot better response from the guys here.

-lars

wasp

i also have a 305 tbi and have covered this topic, i myself will be getting the l98 vette heads, heres a link to the discussion

https://www.thirdgen.org/techbb2/sho...threadid=96343

iroc22

The way I see it, the L31 Vortec heads are the best head out there for the 305 right now. Fast burn chambers, raised runners, kidney shaped chambers they are the best power makers out there. The L98's intake flow numbers arent that impressive, and there would be a lot of work to be done if you wanna use them. Trust me if you arent using the EGR, go Vortec! The technology is just superior to all other heads and dyno #'s have proven it. I have a camaro performers magazine where they compared the L98 Aluminum heads, Vortec and fastburn and the Vortecs made 35 more horsepower and only like 5 ft-lbs of torque.

wasp

https://www.thirdgen.org/techbb2/sho...threadid=96918

wasp

Ozzy88GTA
Senior Member

Registered: Oct 2000
Location: Milton, Fl
Posts: 199
They will fit but you will loose compression. The 305 heads have 58cc chambers while the 350s have 64cc chambers. The valves on the 350 are the same as the 305, 1.94/1.50. The 350 heads have 160cc intake runners.
As far as the Vortec, they will bot up to the block but you will have to use a Vortec intake. The intake manifold bolts are positioned different from the stock L98 heads. Now, the Vortec heads have the same valve size as the L98 heads, but outflow them due to the intake port design.
Remember that by increasing the intake port volume too much, it will affect velocity and therefore you could be trading low end torque for mid-high end horsepower.
Later,
Ozzy


__________________
1988 GTA, 5.0 TPI, TH700-R4, marron w/black
Chevy heart, GM brain, Pontiac soul

iroc22

You will have to use a different intake if you are switching from TBI heads anyway. And SDPC sells pre-86 Vortec heads which means u could use pretty much any aftermarket intake out there.

This only holds true for ported L98 heads. They dont have a velocity design like updated Vortecs, so if you port them, they lose velocity and the runners "swamp" themselves. The Vortecs already have awesome flow #'s to begin with and their raised ports give them the velocity without swamping themselves.

And I mean come on, Car Craft built a 330hp 305 with untouched L31 Vortecs, and Super Chevy found 35 more ponies from swapping L98 heads to L31 Vortecs. The numbers prove it.

If you're really stuck on aluminum heads, I would recommend going with the GMPP Fast Burns. Once again because of the technology.

And if you are into porting, remember that the L98 heads have the traditional intake port design that has pushrod clearances that restrict you opening up the intake. The L31 Vortecs dont have those pushrod clearances.

wasp

i am taking this all in iroc but im just wondering why you dont have those heads on your 305?

wasp

12464298 Cylinder Head "Aluminum Fast Burn"
This head can be used on any 1958-99 283-400ci small block Chevrolet V8 engine with conventional water flow design, but this head cannot be used on any LT1, LT4, or LS1 engines that are designed with reverse water flow. The all new 23? Fast Burn small block cylinder head has the highest performance potential of any 23? small block head developed by GM. The Fast Burn head combines new technologies with the best of GM motorsports and production cylinder head technologies. The design creates tremendous power on engines from 350 to over 400ci. The name "Fast Burn" refers to the head's ability to quickly and completely burn the air fuel mixture, resulting in higher cylinder pressures and more power. The shape of the combustion chamber is designed to accomplish this "Fast Burn" with flat top pistons, so flat top pistons are recommended with this cylinder head. It is not recommended that the combustion chamber be modified or reshaped, as this could decrease the efficiency of the chamber. This head is designed with a .400" deck. This new technology removes material from other portions of the head, allowing for considerably larger ports and water jacketing. The deck also provides unsurpassed clamping force for cylinder head gasket retention. The super rigid .400" deck thickness can be machined down to .340" safely for all-out performance applications and higher compression. Other ways to adjust compression ratio with the Fast Burn head include top of piston design and piston installed height. Unlike the GM Performance Parts Bow Tie heads and most aftermarket performance heads, this head requires no additional porting for maximum performance. In the past, the industry has added material to heads to allow substantial porting, which can result in poor "out-of-box" performance and additional cost. The Fast Burn head utilizes GM Performance Parts' Cast-Ported technology, which means that improvements in flow, combustion and cylinder fill were incorporated into the machining tooling, achieving maximum performance "out-of-box". While additional porting is not recommended, light sanding to remove minor casting imperfections and polishing of combustion chambers and exhaust ports is acceptable. All Fast Burn heads are CNC machined to exacting tolerances, thus eliminating the need for "blue-printing" of machined tolerances, resulting in a cost savings and unsurpassed "out-of-box" performance. This head has taller than typical rocker cover rails, providing exceptional clearance for rocker arms and valve train supports typically used in all out performance applications. The rocker rails are CNC machined for superior rocker cover gasket sealing. Front head faces are drilled and tapped for typical accessory drive bracketry. The Fast Burn head accepts both center bolt and early style four bolt flange mount valve covers. Signature etched with GM Performance Parts logo. Intake manifold mating surfaces are drilled and tapped for both Vortec and conventional raised port style manifolds. "D" shaped 78cc exhaust port and runners provide adequate flow for applications well in excess of 500 hp. Raised runner (.240" higher than conventional 23? head) intake ports with 210cc ports and runners provide adequate flow for applications well in excess of 500 hp. Raising the top of the intake valves provides a better "line-of-sight" through the port and onto the back side of the intake valves. The 62cc fast burn combustion chambers - the most efficient ever to be incorporated on a GM Performance Parts cylinder head - produce higher cylinder pressures by burning more of the available fuel before the piston starts its power stroke downward. By more completely using available fuel, the engine produces more power per quantity of fuel. The 2.00" hollow stem lightweight intake valves are utilized to reduce loads on valve train systems at high rpm's. The 1.55" sodium filled lightweight exhaust valves have all the same benefits of the hollow stem intake valves, and additionally they are able to perform under extremely high-temperature performance applications. This head has specially designed "deep" valve seats which can accommodate up to 2.02" intake valves / 1.600" exhaust valves. Lightweight valve spring retainers combine with the lightweight valves to help ensure long-term high rpm durability. Screw-in 3/8" rocker studs are used, and accept most available roller rocker arms. Uses all conventional "low cost" readily available 23? rocker arms and valve train supports and hardware. This head is a bolt-on 30 hp increase when used on our ZZ4 crate engine. When tested on a 383 ci small block engine with 9.5 to 1 compression ratio and .540" lift roller cam, single plane intake manifold and 750 cfm Holley carburetor, the Fast Burn heads produced 497 hp at an incredibly low 5800 rpm. Total ignition timing to be used on a Fast Burn head will vary based on a number of factors, but most configurations made the most power with 34 to 36? of total timing.
Technical Notes: Use intake manifold P/N 12496820, P/N 12366573, 12496822, or 10051103 with the Fast Burn cylinder head. Use intake manifold gasket P/N 12529094 and eight attaching bolts P/N 12550027. Use Fel-Pro exhaust gasket P/N 1470 for these Fast Burn heads (some trimming may be required for your application. This head includes intake valves P/N 12555331, exhaust valves P/N 12551313, valve spring cap P/N 10212808, and valve springs P/N 12551483




12556463 Corvette Aluminum Cylinder Head Assembly
This aluminum cylinder head assembly for small-block Chevrolet V8s is ideal for street rods, fresh-water power boats, and high-performance applications. GM Performance Parts' aluminum cylinder head assembly combines the benefits of light weight, advanced design, and an affordable price. This complete head assembly includes valves, chrome silicon heavy-duty valve springs, retainers, 3/8" screw-in rocker studs-everything an enthusiast wants in a high-performance cylinder head package! GM Performance Parts aluminum cylinder head assemblies are based on brand new Corvette light alloy castings (P/N 10088113). The Corvette cylinder head's advanced design features include D-shaped exhaust ports that enhance the flow of burned gases, high-velocity intake runners that provide crisp throttle response, and centrally located spark plugs that improve combustion efficiency. Valve seat inserts for 1.94" diameter intake valves and 1.50" exhausts are installed in the 58cc combustion chambers. Raised rocker cover rails with machined sealing surfaces virtually eliminate rocker cover gasket oil leaks. This high-performance cylinder head assembly is used exclusively on High Output 5.7-liter small-block V8 engines. Unlike production Corvette cylinder heads, it is outfitted with special heavy-duty valve springs (see part number 12551483 for technical specifications). A pair of aluminum cylinder heads offers a weight savings of approximately 50 pounds over comparable cast iron cylinder heads. (A bare aluminum casting, less valves and springs, weighs 19 pounds, versus 44 pounds for a bare cast iron head). This reduction in total engine weight of 25 pounds each can improve handling, acceleration, and fuel economy.

Part Number...Description
12555269.........Stamped steel rocker cover
10229162.........Corvette screw-in oil filter cap
12342056.........Chrome screw-in oil cap w/GM logo
12338092.........Valve cover hold-down bolts (8 required)
14094717.........Hold-down bolt washers (8 required)
14088793.........Hold-down bolt gaskets (8 required)
14088564.........Neoprene rocker cover gasket
12557236.........Composition head gasket, .051" thick
12495499.........Head Bolt Kit
12495490.........Rocker Arm Kit
Technical Notes: Technical Notes: This casting does not have intake manifold heat riser or EGR passages. The exhaust port exits are approximately .100" higher than production cast iron heads; exhaust manifolds and aftermarket headers may require modification to maximize airflow. The spark plug holes are angled; check for adequate exhaust manifold or header clearance. Use 3/4" reach gasketed spark plugs with 5/8" hex heads (AC FR5LS), 904, or MR 43LTS. In rapid fire use #8 plug. Both ends of the head are machined for alternator, power steering, and air conditioning compressor mounts. No pushrod guideplates; use rail type rocker arms P/N 10089648. This aluminum head assembly requires valve covers with central hold-down bolts and extra-long bolts with washers. A composition head gasket with stainless steel fire rings is recommended to prevent galvanic action between the head and a cast iron engine block. This head assembly is the same as P/N 10185087, except valve spring and retainer change.



now im confused again,i had some discussions in the past about what head would be best for my 305 ,from what i learned the l98 is the best choice for aluminum. i learned you want anywhere from 54-58 cc chambers optimally to make up for the heat loss in the aluminum..........the l98s come 58 and you can shave the deck to lower that............the fast burns come 62cc plus if you read the tech notes you need a particular intake manifold,i allready have an edelbrock tbi, plus it isnt very sepecific what valves come in the fast burns...1.94 is max for a 305 it says they can "accomodate" 2.02 but doesnt say specifically whats in them unless i misread it..........i still think l98 would be the best choice.........not arguiing with you but now im getting even more confused............

iroc22

Because I have to pass emmisions, so I went for the best EGR compatible head for my 305. S/R 305 Torquer heads flow @ .500" lift 213cfm intake and 166 exhaust.
L98 Aluminums flow @ .500" 199cfm intake and 164cfm exhaust.

Those are both unmodified #'s of course and both 1.94/1.5 valves.

iroc22

Might as well chuck that intake in the garbage if you are going with Aluminum L98s. They have the pre 86 pattern. The Fast Burns come with both Vortec and pre 86 already in the head.

Fast Burns come with 2.00/1.55 valves, they're just borrowed from the LT4. You can go with 2.02/1.6 on a 305 if you like. I have personally looked through the crankshaft valley up at 2.02 on a 305 and it doesnt even come close to the walls and shrouding doesnt even become a factor until lifts of .550-.600

wasp

oh yeah? i was told the l98 would bolt up.....its on a 91 bird so they wouldnt bolt up to my intake huh? but the gmpp fast burns would? i really want to go aluminum not cast iron

wasp

[QUOTE]Originally posted by iroc22


Might as well chuck that intake in the garbage if you are going with Aluminum L98s. They have the pre 86 pattern. The Fast Burns come with both Vortec and pre 86 already in the head.



Fast Burns come with 2.00/1.55 valves, they're just borrowed from the LT4. You can go with 2.02/1.6 on a 305 if you like. I have personally looked through the crankshaft valley up at 2.02 on a 305 and it doesnt even come close to the walls and shrouding doesnt even become a factor until lifts of .550-.600


where ya look up thru the cylinders? and nah my cam is max lift .487, not too big.....so youre saying you have personally examined those says valves from underneath and they clear the cylinder walls easily? also im not doubitng you but are you absolutely certain on those valve sizes in the fast burns?

and from what i read above these fast burns dont require any porting just deck shaving to lower the combustion chamber sizes correct?

wasp

i looked up the part numbers you are correct in the valve sizes......glad i got into this conversation..not only do the fast burns look like a better engineered unit but they have slightly bigger valves as well............

iroc22

Yes yes the if the technology is there, get it! The Aluminum L98 were awesome heads back in '86 when they first came out, but now their design is dated.

Unfortuantely your intake will not bolt up to the Fast Burns. The only heads that will bolt up to your TBI intake, is 87-95 factory iron heads and very few aftermarket ones that specify a 87-95 bolt pattern It's a better design, just not used enough.

If you have a 305 block without the pistons, rods, crank, u can look up via the crankshaft valley to the valves on the heads. I bolted up 2.02/1.6 on a 305 block and they clear easily.

Out of the box the fast burns will outperform most heads on the market and they're pretty cheap. All u need to do is shave them from their 62cc to about 54cc

Note: The L98 Cast iron heads have the same pattern as ur TBI intake (87-95), but the Aluminum L98 heads have the old style intake pattern (pre-86)

wasp

so whats a good performing aluminum intake that would accept a tbi and also bolt up to the fast burns? i could always sell the one i have on this site for a few bucks im sure......also


12464298 Cylinder Head "Aluminum Fast Burn"
This head can be used on any 1958-99 283-400ci small block Chevrolet V8 engine with conventional water flow design, but this head cannot be used on any LT1, LT4, or LS1 engines that are designed with reverse water flow



is there something different about the bolt pattern on a 91 tbi motor? it says "on any" above.................?

wasp

lol man............i dont mean to throw any more twists into this discussion but the further i look the deeper the s*** gets............ive been talking to everyone i can and doing alot of research and i find something and learn something new everytime..............any reason noone has ever mentioned these heads b4?....................






http://www.racesearch.com/PDFCATALOGS/1602/96.pdf

iroc22

Yeah it can be used on any block, but the intake bolt patterns vary. 87-95 Cast Iron heads were a different pattern and all TBI engines were this different design.

The best idea is to get just about any single/dual plane carb intake and make a TBI adapter plate for it. That way there is more plenum volume.

wasp

gotcha, holley makes an adaptor plate, seems easy enuff

iroc22

Yeah the Holley adaptor seems to be the way to go

wasp

know anything about those e-tec edelbrocks iroc? i know its only advertising but they claim to outflow both the fast burns and the vortechs........ hey redbird i hope your printing all of this out,lol you kinda quiet........

iroc22

I havent had any hands on experience with the E-Tecs but they look like the same head to me. The E-tec 170 looks like the Vortec only aluminum, and it seems to be a good choice for the 305. Although all they claim is that they flow 20% more on the exhaust side than the Vortecs, which doesnt tell much. The E-tec 200 is supposed to be the equivalent to the Fast burn head but I think it would be too much for the 305 and better left for the 350s.

Honestly though, to me those E-tec 170 heads just look like Aluminum Vortec heads with CNC intake ports. They are a consideration though if you are willing to spend the money for them. Dont bother with the 200 heads.

wasp

yeah iwasnt gonna go for the 200 mmmmmm summit has the e-techs for 1,000 for the pair plus 7 bucks shipping......the fast burns are 1100 plus shipping............welp either way i go i need a vortech manifold with an adaptor for the tbi.........now heres the next post lol..........im leaning towards one of these 2 unless somone has a better choice



Performer Vortec (Idle-5500 RPM)
Based on the popular and powerful Edelbrock #2101, this dual-plane intake is designed for the street rod, industrial and engine swap market utilizing 262-400 c.i.d. Chevy V8s with 1996 and later Vortec (L31) cast-iron or the new Edelbrock E-Tec aluminum heads. Manifold has provisions for external water bypass and may be used on either Vortec blocks or 1995 and earlier blocks. No provision for exhaust heated chokes. Accepts both square-bore and spread-bore carbs and late model waterneck, alternator, HEI and air conditioning brackets. Available with standard finish or polished. For high performance engines operating from 1500-6500 rpm, see the Performer RPM Vortec #7116 manifold below.

Performer Vortec #2116*
Polished Performer Vortec (non-EGR) #21161*
Carburetor Recommendations: OEM 4-bbl (pre-1981, electric choke only) - Ref. A, F, H, N
Performer Q-Jet #1904 (795 cfm) - Ref. A, F, H, N
Performer #1405 (600 cfm) - Ref. A, F, I, K, N, O
Performer #1406 (600 cfm) - Ref. A, F, I, N, use our #8036 for 1972-78 only

Installation Notes: Recommended intake gasket: GM #12529094 or Fel-Pro #1255. Manifold height: A-3.87", B-5.28" see manifold selection page.


RPM Air-Gap (1500-6500 RPM)
The Original… Our Proven, Race-Winning Air-Gap Design in a Dual-Plane Manifold

Designed for 1955-86 262-400 c.i.d. Chevrolet V8s, the award-winning RPM Air-Gap incorporates the same race-winning technology that’s used on our Victor Series competition intakes. The air-gap design features an open air space that separates the runners from the hot engine oil resulting in a cooler, denser charge for more power. Includes rear water outlets, two distributor clamp locations and nitrous bosses. Accepts all 1976 and later alternator and A/C brackets for the street. The heater outlet boss is angled for proper fit over the valve cover. The temp sensor boss clears all waternecks. For square-bore carburetors only. No provision for exhaust-heated chokes and no exhaust crossover. Not for 1987 and later cast-iron heads and will not fit under stock Corvette hood. Available with standard finish or polished.

wasp

awww man not that air gap one this is the other performer sorry bout that

Performer RPM (1500-6500 RPM)

Designed for 1955-86 262-400 c.i.d. Chevy V8s for maximum power and a broad torque curve for high- performance street/marine. Provides power like a single-plane and throttle response like a dual-plane. Has provisions to add oil fill tube. No provisions for exhaust heated or stock-style choke. Accepts late-model waterneck, air-conditioning, alternator and H.E.I. Will fit cast-iron Chevrolet Bowtie heads, but will not fit 1987 and later cast-iron heads. Will not fit under stock Corvette hood.
See Building a Bowtie 420 HP Package and dyno test results for the 7101 power package.


Performer RPM (non-EGR) #7101*
Polished Performer RPM (non-EGR) #71011*
Carburetor Recommendations:


Performer #1407 (750 cfm) - Ref. A, I, K, 0
Performer #1412 (800 cfm) - Ref. A, I, K, 0
Performer #1413 (800 cfm) - Ref. A, F, I, K
Installation Notes:


Use #8504 Edelbrock bolt kit. Recommended intake gasket: Fel-Pro #1205. Manifold height: A-4.00", B-5.30" See manifold selection page.

iroc22

You probably noticed that the RPM says that it wont fit under a vette hood, that means it will be hard to squeeze it under your hood too, unless you have a cowl hood. The Performer is an excellent street intake that fits under the hood easily. Single planes are the ultimate power making intake but they are usually too high for the stock hood.

The other intake to consider that I like is the Weiand stealth; it has an excellent powerband.

Sonar_un

Ok, this thread is very interesting to me, seeing as how I kinda wanted to change heads later, but my main concern was related to the bolt patterns of heads and intakes.

I plan on getting an intake and Holley 670 soon. But from some of the readings, I may have to do the heads with it at the same time.

I am considering attempting to duplicate NJ Speeder's mods. Edelbrock heads, Holley Dominator intake and Holley 670.

Now, with the intake, could I use it w/ my stock heads? Or would I have to wait till I get heads so the bolt pattern matches up.

That would really suck if I would have to wait for heads. It would almost make me consider to start building up a 355 or 383.

DM91RS

The only thing differance is the angle of the two center bolts of the intake to the heads. You can make the intake fit either style with a grinder easily.

wasp

yeah im gonna do the ram air II hood first, so i dont think it will be a problem, theres a system to these things im sure you know, kinda why ive had my tranny and rear completely redone all ready with an aluminum shaft.........cant understand why some guys do the motor first and them wonder why the tranny or rear craps out

iroc22

All you have to be concerned about is 55-86 heads have all the bolts lined up the same. 87-95 Cast Iron heads have the two middle bolts on each side upright. Personally I like the 87-95 pattern, but you will find the 55-86 more popular. Another pattern is the 96-present Vortec which uses just eight bolts.

redcamaro83

i'm getting the edlebrock tbi intake and i'm not looking to buy new intake w/ vortechs and i want better than stock heads later so... what are my options. s/r 305? where can i get info and who carries them?

i don't mind having a set of affordable heads milled for compression.

oh yeah i also will be putting in lt1 cam. i'm wondering if i should replace or rebuild heads with cam install. if i'm going to have heads rebuilt i could go with these: http://cgi.ebay.com/ebaymotors/ws/eB...tem=1873160612

redcamaro83

would it be wise to have them slightly milled for abit of higher compression?

NJ SPEEDER

if you go with the torquer 305's you don't need to worry about eh compression. they are 58cc just liek stock, so your compression will be the same. if you are plannign to do anything to the heads a littel port and polish clean up work and a 3 angle vale job will do the trick.

later
tim

redcamaro83

NJ i asked about the milling on the 305's cuase i was thinking maybe it would ber form better with a little over stock compression maybe 9.5:1 or a little more?
what's your take on it?