jordanz28ss

Would the vortec heads and lt1 cam be the best setup for a tbi 305 700r4 with 3.73 gears. If not what would be the best cam for those gears?

pimpintheRS

dont know if you have noticed yet but the combustion chamber on vortec heads are 64cc and will drop your compression some say not noticed to much but i still does it...

alot of us tbi guys seem to be looking at the s/r torquers and lt1.. i am personally looking at that with an edelbrock intake(egr).. and it should work fine with 3.73's i am going to use 3.42's
:lala:

ChevalierSS

A good machine shop will mill them down to 58cc. I too have been looking at heads. I was look at the vortec and the 305 torquer heads. I've pretty much decided to get the torquer's for a few reason's
1) No machine work,
2) they already have egr provisions,
3) SBC intakes are half the price of vortec intakes,
4) they come assembled ready for a higher lift cam (an lt1 cam is about the limit the vortec head can run without changing springs).

Your head and cam combination are good, and I think 3.73 will also work fine with that setup. Your engine should be able to wind high enough and still produce power to take advantage of those low gears. I would get an opinion from other's running 3.73 and know their powerband before ordering any.

Eric

iroc22

Vortec heads are the ultimate choice for the 305. Once you sort out all the associated problems, you've got one mean 305. SDPC sells Vortecs drilled and tapped for pre 86 intake patterns, which will help you along.

LT1 cams are nice and cheap, but if you really want more power out of the 305 you can go with a good aftermarket cam. Just compare cams before you go out and buy one.

STUB25

bang for you buck L98 aluminum vette heads are the best choice here hands down for you 305. When properly ported they are running with the AFR 195cc heads!! And you are still running the same compression because they are 58cc. i have so say that the LT1 cma is a good chice as well. If you go with the porting on the vette heads you my want to look at a custom grind cam.(ie:.480/.482 lift @.500 and 206/212 of duration) when running 1.5 ratio rocker arms. just my $.02


D

jordanz28ss

Ok now that you guys have given me all this good info, I have just come across a guy in my area that has a brand new 350 crate motor still in the crate w/0ut the intake and carb and wires..etc......he said he got it for $2200.00 and said he would sell it to me for $2100.00. I think I might bring him up $1800.00 and see if he will take it. Do you think this is a good deal? And if I do this should I go with carb or keep the tbi?

STUB25

you may want to get the specs and warranty info and ask him how long he has had it?

pimpintheRS

i believe that sounds like the 330 horse engine that jprevost is running.. i would keep the tbi jprevost ahs done it...
i would find out warrantyalso and why is he selling it?? sounds like a good deal since you dont pay shipping!

iroc22

The L98 heads are factory castings, so they have pushrod clearances and other various waterjackets that you can run into while porting. They will not run with AFR 195cc heads, they cant even handle running with S/R 305 Torquers.

Quote:

And you are still running the same compression because they are 58cc.

Nope, you would need to mill those heads to roughly 54cc to keep up the static compression because of heat transfer.

brodyscamaro

carb

iroc22

Carb is the easy way out if thats what u want, but if you want more power out of it, you might wanna keep the TBI and work with it (it will be more work tho)

Snowdog 91 Formula

Definitely keep TBI.

jordanz28ss

Ok I might keep the tbi. He told me the he bought the motor for someone else who was going to put it in his car but he sold the car insted and it is still sitting in the crate. It is a vortec 330 hp 380 lb tourqe motor. I am leaning more and more towards buying it off him since I would not have to pay shipping.
Where would be the best place to get the intake for the tbi vortec? And what else is there to do besides 350 injectors and a performace chip?

iroc22

GM did have a aluminum TBI manifold for the Vortec pattern, but the best way to do it is, get a 4bbl manifold for the Vortec pattern and get an adaptor plate.

P.S. SDPC sells the pre 86 pattern Vortec heads.

steve8586iroc

iroc22, I think you have SDPC mixed up with Pace Parts (Jim Pace Chevrolet). They have been selling the modded vortecs for a few years now, check out their web site at www.paceparts.com . There are also some issues to take care of when using these modded heads that will be more trouble if the wrong intake is used. Their new parts catalog goes into more detail of what is nessesary to make them work. These modded heads were originally made for modified stock car racing. It's best to use stock vortecs and a vortec manifold. As for the alum L98 heads they are a vast improvement over stock tbi heads and ported will flow more air than a mild to wlid 305 will ever need. If GM uses unported L98 heads on the ZZ4 to make 350hp and by adding the hot cam can make 385hp, I would think they would be fine on just about any 305. Just my opinion.

Steve

iroc22

L98 heads are a vast improvement over the 187 head, and that's true that GM uses it to make 350hp unported, but it's also true that Chevy High Performance swapped the Vortecs and gained 35hp. They make more power not just because of more flow, it's the added technology. The updated intake ports virtually eliminate the pushrod clearance flow issue, the exhaust runners have been matched to the valve properly, the L98 with its dated half moon shape will not make more power than the kidney-bean high quench Vortec chamber and with the better chamber, the exhaust valve is less shrouded, aided in exhaust gas exit.

SDPC did have L31 Vortec heads just drilled and tapped for pre 86 bolt patterns, though I cannot find them on their website now.

steve8586iroc

I will also agree that the Vortec heads made more power than the L98 heads but that was on a 350. I'm not saying that the Vortecs wouldn't make good power on a 305 but as far as saying the L98 aren't worth looking into is going a little to far. I think that with an LT1 cam and L98 heads he would be far beyond the performance of the stock heads and cam. Way beyond.

Steve

iroc22

I'm just trying to help people avoid spending the extra cash. Once you match the flow #'s and efficieny of the Vortec head with the L98, you've spent way more than originally planned for. You still have to mill the L98's to 54cc, even if you just bolt them on. I agree you will be way ahead of the game in terms of performance, but your wallet will be more empty than the guy with the Vortecs and you'll lose to him; even if you get a cheap pair of used ones, you have to clean them up still. Have you seen the price of new Vortecs?

(steve8586iroc, Im not directing this at you) - forget about the Vortecs being "too big" for a 305. That's an old wives tale. The 492 head on the 68-69 302 had huge flow #'s.

steve8586iroc

Again iroc22 I agree with you in theory but I guess will have to disagree on somethings. Also if he were running a cam that had a 7000+ rpm capability I would agree whole heartedly, another example would be the Boss 302 but there again these engines were made to be yanked on all the time and had very little low end torque. To the point of the original question is yes the Vortec heads and LT1 cam would be a good choice on a 305, a little loss in bottom end tq may not be a bad thing, with some decent mods, ei... Good intake and full exshaust from the headers on to the tailpipe.

Steve

bluemeanney

the best thing to do is find a cam that will be best suited to your engines needs! the best heads are always the ones with the smallest port that flow the most cfm! so go to chevy high performance home page and do some research, they have a chart of some 20 or more heads! oh i think the lt1 cam is plenty of cam for a 305 though

iroc22

The LT1 cam is the perfect choice for a stock PROM 305 TBI.