Please, no putting me down on my choice of starting block size, its what I got, had lying around, don't want to take the time to search for a cheap 350 and dump a few hundred just to make it run. This block runs, and drives, right now, and has fairly low mileage. Work with what I got.

Now then, I was trying to come up with an interesting combo, This is a 305 block from a 1985 Chevy Caprice, they had between 160 and 170HP from the factory. This is what I have done so far:

-Holley 600CFM vacuum secondary.
-Hollowed catalytic converter (it broke itself)
-Imco turbo 3in/3out muffler, single pipe out.
-All MSD ignition (cap, rotor, plug wires) waiting to buy distributor till I get a cam.
-NGK V-power plugs

What I have factory (im pretty sure?)
Stock Intake
Stock Manifolds
Stock Heads
I THINK stock cam, if not its very mild.

Now most people say a pair of headers, I would like to go *** backwards and get headers last on this one because I will buy them new. You will find out why later.

I planned to grab a pair of heads from an 80's or 90's chevy truck that came with a 350. They would be factory 350 heads, I need to know what a good casting number is to look for in the yard. Also, would the chamber size increase be better for the 305, even though it would lower compression. Also should I get them ported & polished?

I planned to buy a matching Holley intake manifold, but I hear the Edelbrock Performer RPM Intake is the best on the street now, is there one slightly lower in price that comes close to it?

CAMS, what kind of a cam would the head-intake-carb setup like, that would give it a rough idle as well as a gain in power, but keep it streetable.

As you see, I'm trying to scrapyard and restore the parts I gather, the only new things I will be buying will be a cam & lifter kit, and headers. ... and a distributor.

I do not have an AC compressor, or a smog pump, no emissions are hooked up currently, all that schnitz went out awile ago. I also have no computer onboard anymore.

I really don't want to bore the engine, I don't want to end up having to buy rods, rings, & pistons, though upon the tear down I might do it anyway, depending on the shape they are in.

Any information would be greatly welcomed, also if your nearby, give me a shout, Waco, TX, 76705.

 

Larger chambers will hurt you because they will lower compression. I'm not sure about the Caprice engines, but in '85 3rd gens got flat top pistons, Caprice may not. If they are dished pistons, you're already too low, and adding larger chambers will only make it worse.

There are no truck heads worth considering until 1996. The 1996-1999 truck engines have the Vortec heads. The 305 Vortecs are better than earlier truck heads, but not better than the 350 Vortec heads. Check what heads your engine has - if they are already 416 castings, then stick with them. If you have dished pistons, do not even consider 350 heads unless you are willing to have them milled to reduce the chamber size. Oh, Vortec heads require a different intake manifold (do not listen to anyone who says the heads can be drilled and tapped to bolt on a "regular" intake manifold - you might be able to bolt them on, but the ports won't match).

Cam - Comp XE262 or XE268, depending upon what you're willing to do with the torque converter. Stock - XE262. Higher stall than stock - you can consider the XE268.

If the tear-down shows you need to rebore the cylinders, abandon the 305. You're dollars ahead looking for that 350 block then. "It's what I've got" is the absolutely worst reason for putting machine shop money into a 305 block.

 

No, there are no good 350 heads in the '80s. The chamber size is big, and that's a bad thing. The heads that are already on your 305 (416 heads) are better. Port and polish those. If you're trying to keep the car driveable, then grab another set of 416s (or 601s from a 305 truck/van from the '80s), and port those and put them on.

That's right, Edelbrock performer RPM is the hot ticket. You want something cheaper? These are 150 bucks ya cheapskate, suck it up! You can get a Performance products model, but their quality control is SO BAD you might lose power over what you have now... ugh, just buck up and buy the manifold. I paid $230 for that manifold since i'm in Canada, and I still think it's a steal. A cast & machined block of aluminum that cheap?!? I don't know how they do it...

You don't want a "rough idle" on a 305. That would suck. Get a compxe256h or xe262h. That's as big as you can go and still be able to drive it. I'd go get a higher speed stall converter, as well as make sure you have 3.73 gears to make sure you're having fun.

I sure as heck hope you have a non-cc distributor to match that carb?!? Otherwise you're probably making about 100HP and getting a solid 8MPG eh? I mean, that should have been done with the carb, it's not a "maybe later, for more performance", it's a RIGHT NOW, to get it to work right.

And yea, do the headers sooner rather than later. I don't see why you need/want to wait on that? All other mods will be choked by the lack of exhaust. A 3" muffler is like a fart pipe if you still have manifolds, and 2.25" single exhaust under the car. Yes, you heard me, I said it's like you have a HONDA STYLE fart pipe. Take that

 

All the Y pipe and exhaust under the car has been converted to a single 3" anyway, a long time ago, not by me.

I understand if the cylinder walls need bored I will just get a 350 block, I have a 355 block sitting, but it needs bored again to clean the walls, making it 60 over.

I knew the Edelbrock performers were cheap but I'm just checking if there was something comparable, and cheaper, I don't mind the price of it.

Would I actually notice a difference porting and polishing the heads I have now? Sorry, know nothing about this part, I just put it together

And what is a non-cc distributor? I'm guessing that means not a stock one, in that case yeah, I make about 8-19mpg right now, and can still outrun MOST things that come my way.

Also: I have 4.11 in the rear end, so gears are taken care of, the stall however, is stock.

Oh and what is the major difference between 601 and 416's?

 

If you have 416 or 601 heads - yes, port what you have and use them. 601's have a slight better combustion chamber and slightly smaller chamber (52 vs58cc).

I'm not sure what was stock on a 1985 Caprice in... whereever you are. In Canada it would be non-cc. In USA, probably non-cc, unless you used your Camaro distributor, and are in USA, then it would be cc.
If it has a vacuum canister on it, you're fine - that's non-cc.

Get a slightly more aggressive stall speed, port up 601 heads, and use the compxe268h. That would be a fun combo.

 

Checked, I have #416 heads, keep or still aim for a 601 set?

By interesting combo, define that, I like interesting things

Also the current stock engine was increased in 85 to 9.5:1 CR, so its interesting as it is.

My current Intake is a 14057053 GMCFM

 

601s are slightly better. If you want to drive your car while you build up the parts, go get the 601s. If you can drive your buick or whatever while you work on your camaro, just tear off the 416's and use those.

port, bigger valves, etc. Then put 'em back on. Much better HP.

I never said interesting - I said fun. Fun =

 

Whel I would be driving a 98 Honda Civic while I work on this, the Caprice was more of a "you got 2 hours to tear the engine and transmission, and be on your way" thing, so I never got the car.

 

you could run a slightly bigger cam then sonix suggested, i run a comp 276hr in my 305 it doesnt have a very ruff idle i drive it on the street almost everyday, and i still have 15in of vaccum