thunder-lips

So, I am in the process of my 383 build. About 1/3 of the way there with parts. I wanted to know if there is difference in 350 blocks. Are certain chevy 350 blocks better than others? Are certain year blocks better than others? I plan on just picking up one from the salvage yard. Two bolt main and two piece seal is the route I am going.

Atilla the Fun

Then you half answered your own question. Since you're set on a 2-piece seal, look for a block with no core shift, and with "010" above "020" cast in the timing cover area. The "ten twenty" blocks are high nickel and high tin, so the bores wear less.

Wadebryant

Would it be safe to assume that this is a fair to moderate $$ buget build? Finding one of the higher nickle contented blocks in a wrecking yard might be possible but odds are probably against you there unless you already know what your looking at and for. Otherwise, if you're building a budget stroker motor for the street, the real costs will be incurred once you take the junk yard block to the machine shop for sonic testing, prep. and finish work.

Before you go to searching through the bone pile, why not ask the machine shop of choice if they might already have a block to suit your build? Might get a better bargin.

Good luck

bart91406

Might I ask why you want a two piece seal block, do you already have your crank? If not than I would look for a one peice seal, they are more plentiful, have a much better rear seal, have a windage tray, and can use cheap factory roller cams.

Atilla the Fun

The best 2 things about going roller are no need to "break-in" the lifters, and getting more lift per given duration at .050", which helps strokers even more.

bart91406

And do not forget about all the cams losing a lobe, even after all the proper steps are followed, what a PITA.

five7kid

iTrader: (14)

Pretty much eliminates what I was going to recommend if you wanted the "best".

thunder-lips

Hi guys. I had already asked my machine shop if they had any blocks, but answer is no. Already got a price for the machine work. About $400.

Ya, this is a budget build. My budget is about $1,000 a month. I picked up a weekend job, and work overtime at my main job to get this engine done. Want to have it done and in the car by june.

As for the 2 piece seal, I thought they were suppose to seal better. And no, I have not got the crank yet.

As for roller cams, too expensive for me. I went with a hyd flat tappet Lunati Bare Bones, @.050 224/234 cent line 107/117.

five7kid, what would you reccomend as the best.

Atilla the Fun

five7kid knows his stuff, no doubt, and I believe he's in the roller cam camp too. The 2-piece seal was causing GM too much warranty work, so for '86 they introduced the 1-piece seal. It was night-and-day better. You can put the cam you have in the later blocks, plus then you can go roller for cheaper later on. For ultimate best, the ten twenty block with a conversion-style set of roller lifters is the theoretical best short of an aftermarket block.

thunder-lips

??? Huh???

Atilla the Fun

Just because all the '87-up passenger car SBCs came with roller cams doesn't mean you can't put a non-roller in there. And if you do start with an '87-up block, that makes it cheaper to run a roller than starting with a pre-87 block and having to use excessively expensive retrofit-style roller lifters.

five7kid

iTrader: (14)

One-piece rear main seals are better than the old two-piece rear main seals when it comes to which seals better.

Quality improved as the years went by, and core shift or improper factory machining pretty much disappeared by the one-piece RMS years. Can't say that about the older engines.

383 stroker cranks are available in the one-piece RMS versions. Many of them are internally balanced, so you don't have to use an external balance damper or flexplate. You can get an internally balanced two-piece RMS stroker crank, but they are generally more expensive.

If you get a used one-piece RMS engine to build that had roller lifters, you can reuse the lifters assuming they haven't been killed with improper maintenance (such as not changing the oil). They will be fine for most street performance applications. A performance roller cam is more expensive than a flat tappet cam kit, but you're getting something better for your money.

Atilla the Fun

internal balance or external balance is about rod length, 5.7 are external, 6.0 can be internal. Internal is better, but 5.7 rods keeps the wrist pin out of the oil ring land, and that's good. For 100,000+ mile street use, it's better to use 5/64" rings, and this means 5.7" rods or custom pistons. 5.7 can be done by reusing stock rods, but this calls for a cam with a reduced base-circle. Aftermarket rods that use capscrews instead of bolt-and-nut will allow running about any cam.

Atilla the Fun

oh, and an "internally-balanced" 1-piece RMS 383 still wants the weighted flywheel/flexplate normally used with any non-stroker 1-piece RMS SBC.

thunder-lips

Alright then, I will go with a 1 piece then. What years did they start making those?

And please stop with the roller cam guys. I know you are trying to help, But I already know the facts and I no they are better . It is not the route I went with.

five7kid

iTrader: (14)

I'm not going to stop as long as you say things that are incorrect. Some people do use the function and if they come across your statement, I don't want them believing it and especially don't want them repeating it in other threads. Roller lifters are better. If that's not the route you went with, that's a personal decision. That doesn't mean they aren't better.

One-piece RMS started in 1986 model year.

bart91406

That is not correct, internal balancing vs. external has nothing to do with rod length. You are correct about the 6 inch rod having the wrist pin in the oil ring, but most piston manufacturers have this figured out. You can get 6 inch rod pistons with 5/64 rings, but there is nothing wrong with running thinner ring lands, as a matter of fact most auto manufacturers have switched over to the thin ring lands in new motors, and some of those motors can go 200,000 miles.


As far as the roller vs. flat tappet, if you buy a factory roller core motor with good lifters, then a roller is just barely any more expensive, you have to spend more on the cam, but you do not have to buy new flat tappet lifters, so it partially evens out. Going with a flat tappet cam may be initially cheaper, but with todays oil a lot of cams lose a lobe, and then the flat tappet cam is more expensive, that alone makes a better performing roller cam a must have in my book.

thunder-lips

Ok then, 1986 to what year will work? Will the block be different from tbi, tpi, or efi?

So what did I say that was incorrect? Aren't roller cams better? I guess it is just a matter of opinion though. I'm not trying to call you out. Just want to get the facts straight.

heff17

iTrader: (1)

i know for a fact the 1-piece RMS chevy block with 880 cast on it is a good block. Im not positive what they came in but this is the block that chevy uses for their zz4 and fastburn 604 motors. We build these at a NASCAR speed shop i work at, we run them 7k rpm and 500hp so it should be fine for a street build. In fact i have a dyno video we ran on our home page. www.performance-enterprises.com its the bottom right hand video. the other motor is a 351 ford

oh yea and its also the block i run :-)

ziggy89

not all true about the one piece rear and a roller lifter

unlucky for me the 350 block i used for my 383 was from an 86 truck
so 1piece rear old heads and flat tappet cam

five7kid

iTrader: (14)

Since the OP intends to use flat tappet lifters, whether or not the one-piece RMS block will accommodate roller lifters is irrelevant.

However, it is correct that not all one-piece RMS blocks will accommodate factory roller lifters. '86 was the first year of one-piece RMS, but '87 was the first year for factory roller lifters.

Candidate blocks would be any 350 from 1986 to 1999, including passenger car, truck, and some factory crate engines of the Gen I type. 1996-1999 Vortec blocks are included, but not LTx blocks.

naf

iTrader: (7)

Later blocks should be checked for a fuel pump rod bore if you're planning on using a mechanical pump. 'Course the shop will likely be able to bore it for you, but you probably want to check the requirement before trying to mount the pump.

Apparently it's fairly common for the rod passage not to be bored on later blocks intended for FI. I have personal experience only with one.

five7kid

iTrader: (14)

Good point. I've seen several.

But, again, an electric fuel pump back in or by the fuel tank is superior to an engine-mounted mechanical. Of course, that may meet the same resistance as roller lifters. . .

thunder-lips

So could I use my TPI L98 block for a carbed 383 build? Will the intake manifold bolt on?

five7kid

iTrader: (14)

The intake bolts to the heads, not the block. So, yes, you could use your L98 block to build a 383, regardless what heads or induction goes on it.

thunder-lips

Chase30

I’m currently looking around for blocks for my 383 build. What would you recommend for the best block. I’ve seen a lot of people use dart blocks. My build will be a street truck and shootin for 475-500hp range for a fun toy. Thank you

Fast355

iTrader: (2)

I am using a Summit Racing 350/383 0.030" over Vortec 880 block. The machine work was very nice on it. It was $789. I had a 15% off promo code. You could not buy a core and have the machine work done for that. No core charge on the Summit block either. That being said the only negative I found was the fact it was a converted 2 bolt block with chinese main caps and hardware. I went to a GM dealer and ordered all the factory bolts and studs. I am using a milodon windage tray that needs 5 of the factory style main cap studs.

I filled the bottem end with Scat crank, ProComp 6" H beam rods, King coated bearings, and Weisco Forged pistons. Should be fine for my application because this will have a rev limiter at 6,000 and shift WOT at 5,800.

I am shooting for about 500 hp and 500 tq to move my heavy Express van around.