LSX376-B15 or TMS 370/408 fully forged?

[stevieturbo]

I'd want to know more about the parts used.

The only listing I see is on Jegs ? it does say Manley parts...which should be ok. Although the rods only state ARP 8740 rod bolts ? Which although good are the lowest spec.
Would be nice to see some ARP2000's there

And although the pistons are forged Manleys..again, would be nice to see if they are aimed towards normally aspirated, or boost.

And at 10.3:1 CR...you'll need to be using very good fuel with boost unless it's very low boost.

[stevieturbo]

On ATK's line, this 427 short block doesnt look bad, and they say only $350 to upgrade to a CCW crank. But it is heavy iron....and despite saying a Dart iron block, their picture shows a GM block lol

https://www.high-performance-engines...-p/sp101-b.htm

[vhawk]

I am afraid I will have to run it on the lowest boost possible in order not to fry my stock trans

Here is what I see in the description:

Horsepower: 620+
Torque: 550+
Block: New GM LS3
Bore/Stroke: 4.065 x 4.000
Year Range: 2008-2017
Displacement: 415CI
Crankshaft: Manley 4340 Forged Internally Balanced 58 Tooth
Connecting Rods: Manley 6.125" Forged H Beams with ARP 8740 Bolts
Pistons: Manley 2618 Forged
Piston Rings: Moly Rings
Compression Ratio: 10.3:1 Compression
Camshaft: Hydraulic Roller
Camshaft Specifications: 240/256 @50 .625/.625 113LSA
Camshaft Bearings: Installed & Clocked to OEM Position
Cylinder Heads: New LS3 Aluminum 68cc/260cc 2.16/1.59
Rocker Arms: OE Rocker Arms with trunion upgrade
Oil Galley Plugs: Installed & Sealed
Weight:412

I asked them if they can lower the CR for my custom build. Shouldn't be a problem, will see.

[stevieturbo]

Also, that is a big cam if it's a turbo build.

I would like better rods in there, and as it seems to be a complete motor ? ARP625 head studs, as they do not mention head fasteners at all.
Either that or 1/2" head studs, although that's more labour.

[eLeSthree]

TMS' complete Dart 1300hp long block with Frankenstein Engine Dynamics M311 cnc'd heads is on sale for $9748. You just cant beat that.

DART SHPLSNEXT 388/427 1300HP

DART SHP LSNEXT

Dart SHP LSNEXT Finishing kit

K1 4340 forged crankshaft 3.622" or 4.000"

Manley H-Heavy 4340 forged connecting rods with ARP 2000 rod bolts

Diamond pistons

balance crankshaft

ACL coated racing main bearings

Cam bearings

This short block is rated to 1300HP

Frankenstein Thompson Edition M311 long block conversion

11* CNC ported aftermarket casting 6 bolt heads

Extreme duty stainless intake and extreme duty solid exhaust valves

Billet Rocker Rails

.660" platnum springs

Thompson Motorsports custom ground Camshaft

Thompson Motorsports custom length Chromoly pushrods

6 Bolt Head Studs

Melling Select High pressure oil pump

Billet adjustable timing set

Thompson Motorsports high RPM lifter set

Trunion Upgraded Rockers

GM MLS head gaskets

GM lifter trays

Thompson motorsports Professional assembly and 12 month unlimited mileage warranty

https://www.thompsonmotorsports.net/...lsnext-388-427

Call Dustin for the sale price, its advertised on Instagram.

I will say, that the build times are running longer than usual due to the given Covid-19 circumstances. Mine ships today.

[vhawk]

Looks interesting

But how much additional stuff and work is needed to fit it into a 5-th gen?

[stevieturbo]

Maybe GM build the best engines ?

https://www.enginelabs.com/news/a-lo...ter-ls-engine/

Although for street use etc I wouldnt be a fan of stepping down to a smaller motor.


But the Dart based options should be able to be bought as a direct swap for whatever you have at present

[eLeSthree]

Originally Posted by vhawk

Looks interesting

But how much additional stuff and work is needed to fit it into a 5-th gen?

The older Dart LS blocks had fitment issues, however the Dart shp ls next block is made to be a direct drop in. Some of the more expensive LS Next PRO blocks dont have skirts for the oil pan to mount, but those are stupid expensive and way overkill for what we are doing.

Mine will be here Wednesday. I'll let you know if there are fitment issues.

EDIT: Make sure you get the $150 Dart Windage Tray Kit. It allows the stock oil pickup to be fastened to the main caps.

[stevieturbo]

See that goes back to a question I asked ages ago.

At a glance, the Dart blocks look good value....but then you need to buy lots of additional stuff to actually make them functional.

[chadbeau]

I am running the b15 longblock with a gt11 cam with a ysi-b at 24ish psi boost, close to the 1kwhp mark with no issues, heads just got pulled off for a full port and valve job planning on turning it up a notch next week when I put them back on!

[stevieturbo]

Another good video...showing how far you can push a setup, even with OEM head bolts !

Although yes...it did let go lol..