Watched a friend's W31 350(now 362) being dynoed last week.
Pretty cool especially after cam breakin & on the third(and final) pull at 6100 RPM!
Mostly stock rebuild with a more modern cam & 9.6 CR/60 over pistons.
Attached is the dyno data, that shows ratings are close to stock(with lower compression). Rebuilder said that if headers were used instead of the restrictive stock manifolds, 30 - 40 more HP could be had.

 

Thanks for sharing, great info ! Any detail on heads ..just 2.0 1.62 valves no bowl work ? Also can you you share cam details? I would like to dyno my build but damn if its 700-750 bucks think I will just go by track mph and weigh it on the nhra scale instead

 

Heads are the stock #6 with the big valves. No bowl or port work, they cc'd out to 68. He used a comp cam with I believe around 492 lift.
Note that using headers over the stock 350 exhaust manifolds will give you around 10% more HP.

See ya on the dyno costs. This shop charges 450 if they do the rebuilt, or 650 if you bring it in. Although if u can afford it, the cam is broken is, tested & tuned for drop in with no issues.

Derek

 

Thanks for the info. The Comp XE268H is .485/.490 and the Magnum 280 H is .490/.490 figure its probably the XE268 except I am surprised it peaked at 5800 with manifolds sometime those XE lobes will "crash" the lifters hydraulics due to aggressive ramping and cause a lower rpm peak due to valve train but can be corrected with extra spring pressure and or lighter components. Might be the Magnum 280 though would be nice to know.

 

Decent numbers considering the manifolds.
But a few things when reading a dyno sheet. Throw out the first and last numbers, they're seldom accurate if they're the start and end of the pull.
And 300rpm/sec is pretty slow, that adds numbers along with the 150* water out temp. 600/sec and 170* or so temps is much more real world.
However it seems it was running a bit fat so he most likely left a few numbers on the table. Nice build.