i just ran into a 350 block and am planning on building it to replace the wimpy 305 in my car now.
after gitting it mechined and tested and all what should i start to do ? i want to keep it carb and im thinking about a forged piston setup all help is greatly appricated since this will be my 1 motor build thanks

 

i'd say connecting rods rated at 500hp or so, if the block came with a crank, get it checked, it may need to be turned 10/10, if not, decide if you want a 350 or a stroked (383) or destroked (330 +/- 4) engine (stroked makes torque, destroked revs, stock is middle ground). buy main and rod bearings you'll need spacer bearings if you choose to build a stroked or destroked engine (clevite 77 is the way to go). have the piston pins pressed onto the rods (forged pistons are the way to go). Then start shopping for cylinder heads and a camshaft....

 

Get headers. Whatever you do, don't do the built 350 and stock 305 exhauts manifolds, lol, this is SOOOOO wrong in SOOOOO many ways.
What kind of power/potential are you looking to get? Is this daily driven one combo shot, no future cam swaps or what?
I get the feeling that you want something with a slight lope at idle but don't want to be getting 6mpg and requiring a 3500+stall TC . Am I wrong in this assumption?
The most popular thing now is to get 450hp out of a n/a 350. It's easy to do on pump gas and with the right heads/cam combo. If you're looking to make less than 400hp, go with vortec heads. Anything more and the aftermarket is the better option. Is there a set budget for the rest of the car or are you just looking for something to bolt right into stock and not rip apart the tranny requiring new tranny mounts every other week .
On a side note, congrats on the 305->350, you won't regret it.

 

What are your goals?

400 HP is alot of power for an otherwise stock car. For a first motor build, I'd suggest that as a reasonable goal.

You don't need expensive bottom-end parts for that. Waste of money. Spend your money on stuff you actually can use, instead of starry-eyed romantic-sounding hardcore racing parts that are unnecessary.

I'd recommend a stock crank with radius-ground journals; stock rods with ARP rod bolts; Speed-Pro flat-top hypereutectic pistons; Speed-Pro file-fit plasma moly rings; a set of Vortec heads; a Comp XE268 cam; steel (not aluminum) 1.52 roller rockers; a Performer RPM intake; a Holley 700 or 750 carb; a set of chassis-specific headers for one of these cars but not for LG4, such as for a 350 TPI, and the cat and cat-back to match, in pother words every single piece from the heads to the street as a set with not one shred of LG4 stuff remaining; 3.73 gears; a 2600-2800 RPM converter if it's an auto trans; & a set of LCAs & LCA lowering brackets. That should put you solidly in the 12s, fairly cheap, and daily-driver reliable if you're careful about how you put stuff together.

 

RB83L69
You and I think along the same lines. Vortec heads are great for a 1st motor and <400hp, anything more and they are a waste of time and effort. I'd say their real limit is probably around 450hp but that requires modifications for larger lift and screw in studs.
As for the bottom end, I agree that a 350 and not a 383 is the way to go. A 350 has 45 more cubes, that's substantial enough and even if the crank doesn't turn out to be straight you can get them straightened for cheap and it doesn't hurt their durability. If you're not going to spray the juice in a blue bottle then don't bother with better pistons. I'd just get standard cast with standard rings, etc. Get the cost of your local machine shop for conditioning the stock rods and then look around for aftermarket or better castings. The most imporatnt part is to use all new fasteners. My friend rebuild his 327 with the original rod bolts and was making ~370hp. We were a bit leary as to how long they would last so don't do it. You don't want something like that to come back and bite you in the @ss after a few hundred miles (not cheap). Also for budget go with hyd. tappet cam, not a roller! Rollers are too expensive and not worth much gain until you get aftermarket grinds with faster ramp up durations. Stock roller cams tend to be no different than a standard hyd. tappet and even then some are worse. The 268 is a perfect cam and it's right at the limits before you need to get the vortec heads machined for higher lift. Don't use 1.6 rocker arms!!!!
Give us a budget and you'll see a lot more of these kinds of replies.

 

Don't get forged pistons. What are your goals???

If you're only planning on making a ~300 some odd horsepower motor, then go with Hypereutectic pistons with Chrome moly-rings.

Also, you don't need connecting rods rated at 500 horsepower unless you plan on making that much horsepower. If this is going to be a daily driver, something that you go back and forth to work with, you'll want it to be RELIABLE, as well as smooth running.

You're likely going to need to rejet and set-up your carburetor for the added HP and cubic inches.


My suggestion, get a good 350 block (you already have), get a decent crane cam, balanced connecting rods, and hypertectic pistons with Chromemoly rings.

That's all you need.

Forged pistons take a while to heat up, and when you first start your car in the morning, you'll get piston slap. This is when the pistons slap up against the cyl wall... obviously, this causes premature cyl wall wear.

The ONLY reason why you'd want to go with forged pistons is if you are putting out 500 some odd horsepower, or using a great deal of nitrous oxide (enough to warrent using forged pistons).

Most likely you're going to just want something that puts out 300 hp. Don't spend more than you NEED to on parts that you won't even really be using. It's going to cost a LOT, may as well get only what you need.. they'll do the job fine.

 

I'd say build a 302 like you'd find in a '67-69 Camaro Z/28

Those 302s (not be confused with 305s) were real screamers with their 4" bore and 3" stroke. If you could get your hands on a crankshaft in good shape from a 283, get it checked and drop it in your 350 block, and there is your 302

Would be a pretty original engine to have in a 3rd Gen car too.. i haven't ever seen or heard of a 302 SBC in a 3rd gen (dunno why though.. killer motor )

 

sh*t I hope u dint hurt yourself. anyway lots of combos to use. what Ive been doing is checking reaeders rides and seeing what combos they r using that r proven to work.

 

ok guys heres the run down im going to put the block in the garage and build it up while still driving my car with the 305 in it after i get the 350 built im going to buy a little beater car and run the bird at the track and hopefully get into some weekend bracket racing. so basically the more money it takes the more time its going to take me to build it

oh ya i also have a recently rebuilt tranny with a shift kit in the car and some new lca's

 

Here we go again...

We won't mention the 283 small journals, or the loss of 50 cubes. And, yes, it was a screamer (screamed for mercy), and as a killer motor, "gets killed by similarly-prepped 350's on a regular basis"...

Oh, I did have such a 302, except it was a SJ 327 block. My 305 revs up pretty much like it did; 305 actually revs higher than it did (improved ignition & cam); gets much better gas mileage than it did, etc., etc., etc.

Build a proper 350, and forget the "different" stuff. If it was really so much better, you'd see a bunch more of them.

 

Yeah, I agree with five-7 kid....

DIFFERENT can be fast ONLY when you dump TONS of money into it.


Like doing something crazy like restoring an 81 TransAm, and then dropping a small block chevy into it... and THEN converting it to Cross Fire Injection just to be different.

Who? What? I don't know anyone who's doing that???