So I did full open exhaust and suspension now its time to start making power! so i wanted to do a head swap but i cant find any heads for a freaking 305 so my question is, just small block heads will fit all small block V8's i can put 350 heads on my 305? is there just certain kinds? also, i know that small blocks are the same size for the most part but can i possibly make my 305 into a 327? or better yet to a 350? what all do i have to do? bigger crank? bore? stroke? help me out please. its time to get some power to the wheels!

 

no, no and no. You could make it into a 334, but that would be a horrible waste of money. Go get a 350.

 

If you are only looking for a mild HP boost go a 70's (non emissions era) q-jet, a nice dual plane intake (Stealth or Performer), 3x14" drop base open element aircleaner and some high octain fuel.

 

What a horrible idea. Why not spend the money on a 350 block to build? Perhaps a better set of heads and a cam? The intake and TBI is not whats holding him back at this point, and putting a carb intake and dizzy on this engine as it is wont gain much, if any.

 

I am happy with my 305, its an LO3 that I swapped heads, cam, intake, to carb.

Id say check that your rings are sealing decent first though.

I went with self-ported 416 heads (58cc 305 heads), got them for $20 and had the guides milled down for .550 lift and valve seats and valves refaced. Machine shop charged $100 for it. You'll need non-selfaligning rockers with these heads. You could score the centerbolt equavilents so you dont need new valvecovers (look at the sittingbull thread on porting 305 heads). Pick up an HEI dist on EBAY for $25, a dual plane intake and a decent cam. I went with the LT4 hot cam (can score used cause its roller for around $80), reusing my stock roller lifters, and am very satisfied (if you have a roller motor). Oh, pin your rocker studs, it costs $3. You might want to save some money for a higher stall converter and gears. You could score a holley VS and rebuild it for about $100 total. Mine went 13.5 first time out, without DRs. Not sure if thats enough for you, but youll have an idea of what it took.

Be patient and do it right. Buy David VIzards book on building High Perf Small Blocks on a budget, great book!

 

Get a set of 305 TPI/carb heads. They'll need to be from 87 up, so they have the same valve cover bolt pattern. Being as how you're in San Diego, best to keep it looking as stock as possible, so you don't have trouble at the inspection station.

Casting number you're looking for is 081.

Do not use ANY 350 heads. All of those (except the 113 casting aluminum ones) will have larger chambers, and you'll lose compression and therefore power.

Look for a slightly larger cam (roller) to put in at the same time. The ones that seem to give the best results usually, are stock LT1 cams from Camaro/Firebird or Corvette (NOT from Caprice or Roadmonster). The ZZ4 cam is another candidate, that you can find brand-new, never-run take-outs frequently on eBay for around $120-140. Runs REAL HARD in a 305. That's about as big as you can go and still reliably pass inspection.

When I lived out there, I used to use Auto Power machine shop up in Oceanside.

Better gears would be the next move, as you proabbly have 3.08s now. I'd suggest 3.42 as the best match to the rest of that combo. Getting a whole rear out of a 98-up LS1/stick car would probably be the best cheapest way to go about that.

 

That actually sounds good. I wanted to cam it but theres a million cams to choose from and i didnt kno which to get. i want to make a lotta horse power so i wanted a good foundation, hence is why i wanted to get a 350. but i didnt think that i could make it happen with the 305. so if i get a crate 350 can i just slap the TBI set up over it and thats that? cuz all these D@M manifolds are for freaking carbs! i heard of an adaptor thing for it though. for 3.42s do i just need to replace the two gears in the back for that? or a whole new rear end? and what all can auto power machine shop do for me as far as money and customer service go? thanks for all the help and info.

 

Sorry, didnt realize you were in CA... man am I glad I dont have issues with inspection. Carb is so easy and cheap to mod.

 

Choose your mods wisely so that all of them can transfer to a 350, and DO NOT touch the 305 short block.

IMO there's nothing wrong or stupid or wasteful about modding a 305, AS LONG AS YOU DON'T SPEND MONEY ON THE SHORT BLOCK. The instant you have to do that, then the cost to BUY and REBUILD a 350 is THE SAME AS, or possibly even LOWER THAN, repairing / rebuilding / refreshing your "free" "paid for" 305 short block. That's pretty much the dividing line, right there.

Right: DON'T buy a TBI adapter. That's not wise. Buy a 4-bbl one, a Performer or whatever Weiand's flavor-of-the-week is that has EGR, and an adapter. There are 2 common adapters; one is terrible, because it moves the TB to somewhere goofy. The other is fine.

So, those heads, and that cam, and that intake, will bolt right up to an appropriately built 350. All youd need, if you swapped the short block, is the bigger TB, and a 350chip, and the 350 knock sensor.Whatever machine work you need. They might maybe even have a set of those specific head castings sitting around ready to go, waiting on the shelf. It would be wise though, to have 1.94" intake valves put in them; they can do that. If Keith is still there, that's who I used to deal with. Of course any good competent honest machine shop would be fine; that just happens to be one in your area I have personal experience with.

To upgrade to 3.42 gears, you'll need to replace the gear set, and do soemthing about the fact that your carrier is probably a 2-series (if it still has the 3.08s that it probably came with). You could either buy a new carrier and make it posi; or buy the "special" thick gears; or buy regular gears and a ring gear spacer. None of those are as cheap, easy, or risk-free as buying a whole rear. Plus, if you buy that particular rear, it will come with disc brakes. One GIANT upgrade in a single package: gears, posi, discs.

 

awesome! what a good idea. so my plan now is to get that 350 short block and im already planning to get a rear end custom by SPOHN. cuz your right might as well do it all once and make life easier, and poss. cheaper! im gonna get a bigger TBI from turbo city, and then a nice intake manifold (edelbrock, or weiand) and combine it to the short block with some bad *** 350 heads and then my hooker headers (2055's). which brings me to another question. is there anyhting wrong with putting a 1 5/8 primaries w/ 3in collectors on a 350? or is it waay better to go 1 3/4? and where the heck can i get a 350 short block thats freaking EMISSIONS LEGAL! and works with the TBI? will those AIR tubes be a problem also? anyone? im gonna hit auto power machine shop up. thanks for all the info

 

They pretty much all are, or aren't, to the exact same extent.... the short block isn't what determines emissions legality (as I found out when I moved out there, and had to replace the engine that was in the car, and like an idiot, rebuilt the stock 305 ... thinking they'd look at the casting # or something .... I know better now...)

Likewise, short blocks ALL work with TBI; they couldn't care less what sort of a thing puts the fuel in.

For inspection purposes, you might HAVE TO use the stock TBI manifold; I don't know that there are ANY others that are CARB certified. Remember, if the EO # doesn't cover YOUR YEAR & MODEL of car, it will fail. But an intake takes less than 2 hours to change out, so it's not a big deal, come inspection time.

All you need, if you want to go with a 350, is yerbasic flat-top standard sort of rebuild; not a slap-together assembly-line "rebuilder" rebuild, really, since that's for people who don't care how it runs, just as long as it does; but nothing exotic or extraordinary either. But, if your 305 short block is still good, you can put that off for the time being. Keep in mind, all that other stuff like intakes and heads and exhaust and cams, ALL can transfer over to a 350 LATER if you choose it right; you can use your 305 for as long as it holds out, and then when it retires, throw it in the trash and upgrade it. Just, DO NOT do what I did, and spend money on a 305 short block. I wish I hadn't done that.

No the AIR tubes will not be a problem, unless you damage them. You'll HAVE TO buy headers that have them, so just be careful not to wack them while putting them on.

1-5/8" is probably fine for most street motors. 1¾" is better for a little more of a max-effort situation, but still OK if that's what you find. Don't just get the cheeeeepest thing you can find that says "headers" on the box. There are few things worse than headers that don't seal, scrape the ground, fall off, rust out, don't fit the chassis, and so forth. I've had good luck with Edelbrock TES and SLP, both emissions legal with the AIR tubes. SLP doesn't sell them any more though, but you can sometimes find them used. You might want to check out Dyno Don's headers, I haven't seen them but he's somebody that knows what he's doing, so I'd expect them to be good. Don't get all hung up on long-tubes, "true duals", and all that other buzzword crap; that's a sure road to trouble, for someone without good detailed knowledge of what theyr'e doing. Stick with a stock-like arrangement. Get them coated if you haven't already, the coating is the most wonderful thing to come along and happen to headers in my lifetime. It's WONDERFUL. Keeps em looking good, holds down underhood temps (which is a BIG deal, if you like all your wires, hoses, vacuum lines, sensors, and whatever else, not to be constantly turning to dust and falling to pieces), and even makes more power.