i have an 85 305 sport coupe my engine vin code is H i dont belive it is a high output.

1. can i get a rebuild kit with aluminum pistons or is that bad
2. is it supposed to be a flat piston style or dished
3. what size is the stock pushrod size of the stock motor

thanks

 

oh and one other thing sorry what is the difference in the the high volume oil pump and regular do i need high volume does it really matter on my little 305

 

Hey - NC here too - Raleigh area.

My two cents - for what it costs for a rebuild kit, and the time/trouble to do it, I'd get a 350 to drop in it and call it a day - a much funner day!

 

you show me a 350 that will only cost the 329.99 the rebuild kit will BOLT IN and i will

 

Check craigslist.org or the local classifieds. You can score a good used 350 + basic rebuild kit in PA for that much or slightly more easily. It will physically bolt right up to everything in the engine bay you have now as externally a 350 and a 305 are identical. The only other thing you might have to change is the chip in the ECM. Since you're probably carbed it might be difficult finding someone to burn one for you. I never really looked into chip burning so you'll get a better answer from someone in the PROM burning section.

As for the pistons, I don't recall finding anything but aluminum pistons when searching for rebuild kits for my engine. The only choices really are whether you want to use the hypereutectic or forged pistons. Hypereutectics, or hypers, are cheaper and weaker than the forged pistons. However, unless you're planning on running a turbo or supercharger on the engine they should hold up just fine. Hypers are OEM.

The stock pistons in the engine now should be dished.

I'm not 100% sure of the stock pushrod size, but I believe its 7.8"

As for the oil pump, either one will work as long as you have good pressure. The extra volume pumps are to keep up with high-RPM engines. If you're doing a stock rebuild you can use either one. I used a stock oil pump in my engine rebuild. The main thing here is you want to make sure the pickup is set correctly so that it is always submerged in oil in the pan.

 

"Word on the street" does alot of good in this **** poor economy when engine hunting as well. 3 years ago I let everyone know I had $600 to throw at a 350, and within 3 weeks I had a guy begging me to buy his - so I got a fully built ready to drop in carb-to-pan 350 for $600 - and that's when the economy was good! Today, when everyone is trying to make one of the 4 mortgage payments their behind on, no telling what kinda deals you can score!

 

well i will give it 2 more weeks of searching because i just had a hip surgery and will need more so i can no longer physically keep up with the demands of this car so like i said i will give it 2 weeks and try to find one but odds are unfortunately i am going to just have to sell the car. thanks for all your help guys.

 

well it looks like the cheapest full 350 around here is 300 and that is all it will cost me for the rebuild kit and the rebuild on my 305 so i guess it isnt exactly more cost effective to build a 350 maybe more appropriate in the long run but not nessecarily more cost effective

 

the original 305, 350 GM blocks came with aluminum pistons. If your crankshaft has just a touch of wear, a high volume oil pump will compensate for the wear, and a flat head piston will give you just a little more compression than a domed piston. A little advise, hit the junkyards man. The engine may be hard to find but hears a little secret. Check out the casting numbers on a 87 IROC Z camaro 350 block. More than likely youll get a casting number of 14093638. That casting number belongs to a IROC-Z, or a GMC van, or a truck. This very block is also the power plant for the 80's Corvette. In other words, dont just look for a Camaro block. Here is a list of casting numbers that you can use as a guide line if you decide to hit the junkyard (350 block)----- http://www.chevy-camaro.com/chevy-ca...es.asp?group=6
or the 302, 305, or 307 --- http://www.chevy-camaro.com/chevy-ca...es.asp?group=4. I hope this works out for you bro. OOOOOHHHHHH! If you find a block that is just laying around at the junk yard, check for cracks or holes in the block. if it looks good, take out the spark plugs and try to turn the engine by grabbing the harmonic balancer and turning it clockwise. If the harmonic balancer (crankshaft) doesnt spin with relative force, then more than likely the block is siezed. Make sure the spark plugs are out so that there wont be any compression which will not let the crank turn. Make sense? Engine codes are different because of the performance package (TPI verses TBI). Engine codes make the difference between what is mounted on the block like lets say intake, but the casting number identifies the tyoe of block period. Becareful when you find a block, even though a casting number is the same on 2 different blocks, the mainbearings may have 2 bolt or 4 bolts. the way to verify this is by taking off the oil pan.

 

That rebuild kit is not just a "bolt in" deal. You've still got to get the block/crank/heads/pistons refurbished while you're at it. Your bores are likely out of round, you'll need to get them bored and honed. You'll need to get the deck checked, the mains checked, the crank checked, the heads checked. But the big thing is your bores are most likely out of round, so you dont even know what size piston you need yet to buy a rebuild kit. And yours is an 85, so it's a flat tappet cam, so you'll probably want a new camshaft while you're at it.

Either way, point is, there's a whole lot more than just throwing parts at it. All the old parts in it need to be inspected and checked before it goes back together and the block needs to be returned back to original tolerances.

Get a 350 and call it a day. A rebuild will probably end up costing you (Because of all the "well, I might as well go ahead and replace that..." parts) $1k or so.

And for the record... most all sbc and probably most average gasoline engines' pistons are made of aluminum, mostly I believe because aluminum is the best compromise of weight and strength. Beyond that, you can get cast or forged pistons. Cast pistons come as normal pistons or hypereutectic. Hypereutectic have extra silicon added, hence the "Hyper" part. It's extra silicon added to them that makes them stronger. They're brittle and cant handle much detonation, but tehy're tough. Regular cast pistons are kind of crappy though. Cast hyper pistons are going to be lighter than forged ones also so your rotating assembly wont be as heavy. They are physically slightly larger and seal up the bore better too I beleive since I think I recall reading that forged pistons expand more when warm, so the cylinder wall clearances have to be a little larger. So basically, hypers are what you're going to want to go for unless you're pushing 500+ hp or using power adders.