That 33032 GM long block is around $6000. With a GM warranty.
Hard to beat.
You can likely get it for less thru your contact.
Building your own will likely run you 4500 ish, and zero warranty.
Pretty close and it will not run any better.
The build it one will take a couple months, vs a week.

 

The advantage to building my own from a new block is I can build a bit less HP into the engine and make it more cruiser friendly... maybe? I would have the short block put together by the automotive machine shop and then I just have to bolt on all the parts.

JT

 

GM routinely supersedes an older P/N with a new one; perhaps when production site changes. Or a slight physical change. Older L31 P/N x167, most recent x080. Over course of thirty yeras production, L31 replacement engines have had perhaps 4 to 6 different P/Ns.
TODAY, There are TWO different L31 ... the other updated P/N is the Heavy Duty version L31 P/N 19432779, for a few bucks more than standard, it has pressed-in Stellite (hard alloy) exhaust seats. GM's Standard ex seats in sbc began heat-hardening the iron for MY1971 (in advance of Unleaded that was known then to certainly arrive; perhaps to help prevent warranty claims). When an old but '71-up head is very clean from say bake n blast, you can see a faint 'rainbow' around ex seats; clear evidence it was heat-hardened, either by flame or induction). L31 standard will have that rainbow, But L31 HD has pressed Stellite.

FWIW, SRC's commercial heavy duty segment offers cryogenic treated Vortec heads.(that's separate from its GM-branded offerings)..L31 not just GM lite-medium trucks .... Gensets, Irrigation pumps, fracking, marine power. L31 proven VERY reliable.

If you run that 350/357, I'll be gob smacked if it REQUIRES Premium Pump.

 

Camshaft Duration (@.050 in): 215° intake / 223° exhaust

That is a pretty cruiser friendly cam duration.
It is 20* bigger than your original, but also 10* smaller than an L46.
If you cut the duration a couple degrees I am not even sure you would notice.

That is a great cruiser cam!

Your original engine had a very low 8:1 C.R. and this one is 9:1 that makes it much more responsive.
The CR might give you 10 HP and the cam might give you 10 HP, but it is the modern vortec heads that give you most of the HP difference, they likely add 40 HP.
Yeah I'll bet it runs on regular gas just fine.

But yeah, if you want a real expert to spec you a cam, go with Mike Jones. He is the best there is.
http://jonescams.com/

 

GM P/N 24502476 is same HFT cam as in both 350HO and x602 CircleTrack race crate (both have iron L31 Vortec heads).
GM P/N 24502476 is a Very good Hydraulic Flat Tappet Cam .435"/.460" 212/222 112 LSA
Too bad GM didn't both have it back then and installed it in L82; 'specially those L82 backed by an auto. They'd have been more responsive in daily traffic.

 

Kind of a crappy thing to do ordering an engine and then sending it back because you have buyers remorse. Wonder how much they are going to hit you for shipping and restocking......

 

You can't tell me that in your life time you never bought the wrong thing then returned it... if I have to pay freight then that's my lesson to not panic and buy the wrong motor and I don't have a problem at all with paying freight because it's my mistake.

It was a no problem with Blueprint to return the engine.

JT

 

^^^THIS^^^

Perhaps Norris' own supply chain management 'procedure' is at root of this failure of BPE to meet customer demand in a timely fashion ? In today's biz, that's Now.
Perhaps those metrics aren't even recorded; much less tracked ?

What If ?
What if Norris had ensured his product was available and in stock at all usual retail outlets ? Perhaps there would've been no desire for a return; what if ?

What if OP simply buys local ? If and When that course is set; even a less-desirable result can be addressed and resolved quickly & locally. Interstate ? Not so much.

 

Doing some research on the Chevy 350/357HP 19433032 long block and mostly using the Performance Catalog as my reference and sometimes AI.

HP 357 Bore 4.000" Stroke 3.480"
Compression Ratio 9.6:1 or 9.0:1 depending on where you look the 2026 Performance Catalog shows 9.6:1
Intake Valves 1.940" Exhaust Valves 1.500" Chamber 62cc Intake Runners 170cc Exhaust Runners 61cc
Intake Lift 0.473" Exhaust Lift 0.473" Intake Duration 215° Exhaust Duration 223° LSA 108°

Engine Components Breakdown

Block (P/N 10105123): Cast iron, 4-bolt main caps.
Crankshaft (P/N 10243070): Nodular iron, 1-piece rear main seal.
Connecting Rods (P/N 10108688): Powdered metal.
Pistons (P/N 88894280): Cast aluminum.
Camshaft (P/N 12677151): Hydraulic roller, .473" intake / .473" exhaust lift, 215°/223° duration @ .050".
Cylinder Heads (P/N 12558060): Vortec cast iron, 64cc chambers, 1.940" intake / 1.500" exhaust valves.
Rocker Arms (P/N 10089648): Stamped steel, 1.5:1 ratio.
Included Components: Oil pan, valve covers, and timing cover are installed.

With an LSA of 108° what will the idle and vacuum be like?

Ai suggests:
LSA Effects on Engine Performance

Tight LSA (106°–110°): Creates a "choppy" or "racing" idle, lowers vacuum, increases mid-range torque, and is often used in carbureted or naturally aspirated engines.
Wide LSA (112°–118°+): Produces a smooth idle, high engine vacuum, improved drivability, and is better suited for EFI, supercharged, or turbo applications.

JT

 

Hmmm...
Very interesting that is is hard to find complete cam specs for this cam.
I Iooked also.
I have a hard time believing it has a 108 LSA, if it is made by GM, it idles well, and is "easy to live with" as many have reported.
So that 108 is false.

A conversation over on Speed Talk revealed this useful info:

• Chevy does not specify the LSA on that cam.
• It has Asymetrical lobes so LCA is not typically listed, or useful.
• Most street Chevy cams have 112-114 LSA, not a tight one like 108

There was also a recommendation by Mike Jones of Jones Cams, he is a frequent poster over there:
<quote>

Re: Chevy SP350/357 cam #12677151

Post by CamKing » Mon May 27, 2024 12:32 pm
skinny z wrote: ↑Mon May 27, 2024 11:20 am
The guy I'm inquiring for is putting together a "mild" 350 with 059 Vortecs. (Small chambers to help crutch the dished pistons that are .025" down)
RPMs will be limited to less than 6k by his reckoning.

IF he wants a GM cam, look at # 10185071.
That's what's in the 604 Crate engines.
It checks: 268/274 @.006"
209/222 @.050"
.316"/.340" Lobe Lift
.474"/.510" Valve Lift, w/1.5 rockers
112 LSA

This will work with stock lifters, and the GM beehive springs # 19420455
Mike Jones
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com

<end quote>

When it comes to cam specs, you will get 100s of recommendarions, from 100s of supposed "experts".
But consider the source, and their experience.
Jones Cams is very likely the single most revered cam expert in the US.

Using Jones full cam specs, I got a 17.3" vacuum even at a very low 700rpm idle. Very easy to live with.


The 6* difference in the intake duration between the 2 cams listed, should have very little noticeable difference.

If it were me, I would use the more modern GM grind they use in the crate motor. GM knows a thing or two...

My take:
That 357HP motor is very mild.
Take the great vortec heads off and you have like 310HP.
Basically a nice mild 300HP 1970 base 350 L48.
But those vortec heads make way more power, with zero driveability downside.
You can hardly compare them to stock '70s heads.

I tuned one of those cams, and it was great street cam, mild idle, power from idle to 6000.
Very wide power curve, and great mid range.
A lot to like.

 

Thanks for all that research on the 350/357 engine!

JT

 

https://67-72chevytrucks.com/vboard/...d.php?t=255659 (article detailing measuring x395 roller specs i.e.109 LSA)

https://www.gmperformancemotor.com/parts/14097395.html (GM display add for x395 roller)

comparison
GM roller cam 14097395 is OE stock in all those serial production L31 Vortec motors And in HT383 "truck towing" crate And in new L31 replacement motors.
I've driven dozens of chevy-gmc pickups w/ L31 (some were new or near-new, dang smooth cam in a smooth, capable motor.
14097395 is on a 109 LSA --- read thru data at first link where a gent went thru the whole rigamaro to DIY Cam Doctor; plotting specs.
so, I've no difficulty accepting the 'newer' x151 roller in 350/357 crate is on a 108 LSA. If mixture & fire's right, it ain't gonna lope and shudder.

Also, that x071 roller in x604 CT crate (FastBurn 210 runners) referenced, that Jones recommended --- that's also the very same cam in Yesterday's ZZ4, ZZ5 & Today's ZZ6 crates. It was also in now-obsolete & long-discontinued x603 CT crate (ZZ4 heads). For those who've driven a ZZ4, you'll know what it can/can't do best.

 

Doing some research on the Chevy 19433032 350/357 and AI suggests that it requires an externally balanced 12.750" 153-tooth flexplate for automatic transmission applications.

My flexplate is 168-tooth... I'll have to measure the diameter of it.

Is there going to be an issue with the starter? Or is the starter located in a slightly different spot?

Edit: My current flexplate measures about exactly 14.125"

Edit: The torque converter bolt circle measures about exactly 10.750"
JT

 

Looks like this might be the correct flexplate.

JT

 

Yes, that is 168T larger flexplate. That one has SFI cert for racing, SFI likely overkill here.

OTOH so does this one fit --- Pioneer P/N FRA-159 --- it is a $42 OE-replacement. (checked into my Pioneer catalog as well)
https://www.summitracing.com/parts/pio-fra159

*all of the above have 168 teeth, external balance to fit MY1987-up sbc with ONE-Piece rear main seal cranks. Like that GM 350/357 crate.

you might go to FLAPS or GM dealer parts dept & ask for flexplate to fit a 1997 Chevy silverado with vin code "R" 350ci/5.7L with automatic transmission.

 

350/357 does Not REQUIRE 153T. phoock AI
It does REQUIRE a 3.00" diameter bolt circle on crank mount flange ... like all One-Piece RMS Gen 1 sbc cranks have.

ALL of the above have TWO sets of (3) TC holes (most do for different TC bolt circles). You'll use only One set of (3) TC holes.

a base 350/357 will also REQUIRE a damper And it MUST be NEUTRAL balance. I suggest a new one. Both GM and Pioneer market very good ones. Again, I think SFI race cert is overkill here.

 

Hmm, Pioneer P/N FRA-159 at Rock Auto is only $33.

JT

 

Starters:
smaller 153T flexplates-flywheels are paired with starters having Two bolts that are in-line AKA straight-across from one-another. The Two bolts re Unequal lengths
OTOH
larger 168T flexplates-flywheels are paired with starters having Two (equal-length) bolts that are staggered AKA offset from one-another.

I recommend modern, starter like what GM has employed to supersede the Old 10MT direct drive starters.
The modern starter designated PG260 aka PMGR because; it has Permanent Magnets (in lieu of heavy, amp-hogging field coils & pole shoes) And have an internal planetary Gear Reduction. New PMGR starters Require New Specific Bolts, weigh less than Ten pounds and have an excellent service record; proven over past Thirty-plus years of OE.

Here's good choice from Rock Auto w/ life warranty REQUIRES NEW BOLTS, some guys have received them with this starter. Works with or without points ign and is configured to fit 168T flexplate. WAI GLOBAL P/N 3510NPG

https://www.rockauto.com/en/moreinfo...t=4152&jsn=643

 

See my last post on starters and get your starter at RA also.

 

My starter looks almost identical to that WAI GLOBAL P/N 3510NPG



Edit: it looks like this Bosch starter

JT