I just helped my brother put together and drop in his new motor. It's 350, thing is he's using 305 heads that have had the valves punched to 2.02/1.60, and the combustion chambers have been made bigger. His old 305 heads were in real good shape when we pulled them off so I took them. I was calling machine shops today and got mixed answers. One shop said they would do it another said it couldn't be done. If it helps, the heads are from an LB9 305, I'd really like to use them if I could, they'll be going on a 383.

 

Lagre chambers are the last thing ou want to do.
The larger the chamber, the more detonation prone they are.

For the bucks to do what you want, yoou'll be further ahead to get some later model 350 heads, The L98 AL vette heads are nice, and depending on what intake you want to run Vortecs are even better. Scoggin Dickey had a real sale on heads some time ago and it still might be in effect.

 

If you put Vortec heads on a 1987-1989 style block, you've got to change the camshaft, lifters and all that stuff besides the intake manifold, don't you? Or at least, that's what I've heard.

 

You are right about the intake manifold. I have to buy that for my vortecs. But I never heard about the camshaft and that other stuff... That doesn't even sound right. The srock vortecs have something like a 450 lift tolerance. But if it is different, the least you would have to buy is pushrods. But I don't even think you have to do that. But the vortecs are great heads, if I do say so myself.

 

Vortecs require self-aligning rockers and a Vortec-specific intake manifold. Pushrods are dependant upon the type of lifters used (flat or roller - cam has to match the lifter type, too).

Back to the 305 head question: 58cc chambers will make compression very high on a 383. Making them "larger" will reduce the tendancy for detonation (not the other way around), but the material available will be questionable (more prone to cracks or hitting water when doing that). Several people have put 58cc chamber heads on 350s with some success, but putting them on a 383 is really stretching it. The port flow will not be adequate to support the higher RPM power the 383 will want to make. I wouldn't say it "couldn't" be done, but I would say it "shouldn't" be done.

You'd be better off with World S/R Torquer or Sportsman II heads on that engine. AFRs would be even better. I'm no particular fan of Vortecs for several reasons, but even they would be better than LB9 heads.

 

Don't use the 305 heads, go with some decent heads or if you have the money go with the AFR's.

 

Say I was to buy a set of Vortec heads for a 350 with hydraulic roller cam and lifters, where would I buy a new intake manifold for it (need a specific part # or link to a website that I can easily find it at) and would that intake work with my TPI? (i.e. would the bolt holes and all that stuff line up correctly without having to make modifications?) I ask this because I too am swapping my 305 out, for a 350, and am interested in the Vortec heads because I've heard on here that they are excellent, and read in magazine articles about their efficiency and durability. I'd appreciate a bit of advice about this myself, so if someone could please offer it I'd appreciate it. Thanks.

 

See that's the thing guys, I don't have the money to buy aftermarket heads. I'm 19 and I'm just trying to get the engine and drivetrain together before I leave home. I have a $3000 budget and about half of it is going into buying the motor and having the bottom end built. $7/hour isn't enough to buy brand new parts all the time. I'm just trying to save myself some money right now, new aftermarket parts will go on this motor, but only when I have enough money to do so. I just need to get it assembled and running(engine, rearend, and tranny) before next June, but still have enough to get an apartment.

 

IF you could find somebody to do it, it would cost a lot and wouldn't flow near the air that Vortecs do.
I think you are going to have more headaches trying to do what you want.
Heads should not be a compromise.
Get the Vortecs, and have them re-drilled so you can use your original intake. It's possible if the machine shop knows what they are doing.

 

You can't redrill Vortec heads and make them work correctly. The ports are in the wrong place, and don't line up with the ports in the older intakes. If you intend to use your existing intake, like if you have TPI and the S-D base price scares you off, they won't fly.

About the dumbest thing you can do in hot-rodding is to spend lots of money on inferior cores. Head cores are so cheap compared to the machine work you put in them, it makes no sense to spend all those cubic mega$$$$ on a bunch of crap, when you can spend a little bit more and get something not so crappy to start from.

Don't get the Vortecs unless you are also willing to buy an intake that fits on them. Don't waste time, effort and money on small-port 305 castings to go on a big motor, they'll still be small-port castings no matter what size valves you jam in them. There are times and places to economize; heads aren't it. Refrain from buying a bunch of chrome and other useless gewgaws and spend your money where it does the most good.

 

NO, NO, NO!!!!!!

"Possible" and "right" are completely different concepts. Since the ports are relocated on Vortecs, just drilling bolt holes so an old-style intake will bolt on to them will NOT produce a good-flowing system - sometimes it doesn't even produce a system that will seal.

Duke, if budget is your primary concern right now, build the 383 shortblock and put the 305 heads on as they are with nice thick composition head gaskets. Don't bother spending any machine shop money getting bigger valves or modified combustion chambers. Do plan, however, on filling the tank with the highest octane pump gas for the time being. Those heads will really choke the 383, so when you've added enough funds to what you had intended to spend on modifying the 305 heads, replace the heads with something better.

 

There is a company that sella a lower TPI intake that fits the vortec head bolt pattern, if I find it again, I will post back

 

found one , check out
http://www.sdpc2000.com/htm/vortec_tpi.html
one bad thing, it costs $400 + $61 if you want working EGR

 

OOPS
Guess I was mis-informed about the re-drillilng.
Thanks for setting me straight guys.
I agree with the "trying to make things work" theory. Just get what works together so you don't have to deal with it!

 

The GMPP Fastburn aluminum heads come drilled for both style intake bolt patterns. Why they do is beyond me as a non Vortec intake will not work with those heads anyway. Been there and tried that.

 

Doing it right now. Old style intake holes are through holes into water jackets, so you have the seal the bolts. Performer RPM matches Ok at best. Vortecs are cast iron versions of the LT1 head as far as I know. The setup I'm running right now is good for a 14.4 at 95 mph. I might be able to run a 14.2 on good air with lots of tuning, but it looks like that's the limit. It's going down this winter for porting and port matching, and possibly a new intake. I'm going to have to inspect it to see exactly how far off the ports are. Vortecs intake ports are raised, so they don't match perfect, but it's not like it won't run at all.

 

You know what, thanks for all the advice guys but I think I'm gonna do this my own way and make my own mistakes. 383 or 400, it really doesn't matter to me right now just as long as I can get it together. I've found a machine shop in town that sells new Dart cylinder heads(complete) for $650. I seriously stressing out about this and it has become not fun. So as of now I'm taking my own advice and doing things the way I want to. After all, that is what it's all about, right? As soon as I can find a good block(for not a lot) I'll start building and I'll post my progress. Once again, thanks for your advice. Sorry if this is long, but it just had to be said.