Which build (block) is going to live longer 351w:

[thomas butt]

Which block, caps, bearings are going to live longer with these builds?

16psi of boost making around 700-800hp max, good tune & factory '69 Windsor block:

351w with a stock stroker kit, 5,500 rpm max

408w stroker, 5,000 rpm max

Forged, neutral balance 408w stroker, 5,500 rpm max

All would be aftermarket stroker kits with aftermarket cranks, 4340 rods, forged pistons & a fully machined block & careful assembly by a pro.

[travis]

I would be looking at an aftermarket block at this power level. That is right on the edge (if not a little over) of where a fully prepped block with stud girdle starts splitting

[englertracing]

Get an lsm block....

[mag2555]

So only the 69 block would be run with boost?
If so I would not go anywhere near the 700 hp level without Aluminum Rods, a girdle and a custom 8 counter weight Crank!

[thomas butt]

I would be looking at an aftermarket block at this power level. That is right on the edge (if not a little over) of where a fully prepped block with stud girdle starts splitting

I would consider it but would first like to try this block. If I have to drop the power level to 650 max then so be it. I am not sure of the limitations but do know limiting the rpm helps tremendously.

[thomas butt]

So only the 69 block would be run with boost?
If so I would not go anywhere near the 700 hp level without Aluminum Rods, a girdle and a custom 8 counter weight Crank!

Sounds good. I thought modern day 4340 rods help. What brand aluminum rod do you recommend?

I will just limit hp to 600-650 if 700 or more is excessive at those rpms.

Does more stroke (3.5" vs. 4.0") WITH a low rpm, under 5,500 have an effect on longevity?

[DaveMcLain]

Aluminum rods can help tremendously when it comes to keeping flimsy parts together at high power levels. About 15 years ago I helped a friend build a blown alcohol Chevy 350. Production block, filled to the bottom of the water pump holes, stock caps, stock forged crank, Manley aluminum rods, TRW lightweight flat top pistons. He used to bury the Autometer Monster tach on nearly every pass and it ran 8.80 in a 3200lb pickup for more than 100 passes without failure. I don't think it would have done that with a steel rod.

[mag2555]

Stroke is a factor, but first and formost it's the G force loads on the main web that go up with the square of the rpm!
If you can make the same HP at 6000 with more boost like you could at 8000 then you have cut in half the loading on the block.

[englertracing]

http://www.lsmeng.com/Billet-Blocks.html

[piston guy]

Aftermarket iron block. The 351W block ( even the '69 version) will split the main webs at that kind of boost/power. You could waste money adding aftermarket caps , but it will still fail. Get the aftermarket block with 2.750 mains for less heat and more strength.