i'd reserve the DEH cams for applications where the exhaust side needs a crutch, like with the 1975 & up D% heads that have the choked exhaust port, or an app that needs a full length X system restrictive quiet mufflers. the early 2V heads have really good intake/exhaust flow ratio w/o porting, single pattern cams do run really well with them

if you do choose a DEH from any manufacturer, watch the overlap. too much overlap will dog out a Cleveland faster than a drunk chevy guy at the local dirt track. Cleveland heads, with their large valves/cubic inch ratio can get into 'overlap trouble' quick because the large valves work so well in the overlap period while both valves are open at the end of the exhaust stroke & the beginning of the intake stroke. because of the valve size and the canted configuration helping the Cleveland breathe better than any comparable size engine, overlap needs to be kept in check... because the heads work so darn good!

the factory iron 4V heads don't have quite as good an intake/exhaust flow ratio, but single pattern cams still work gangbusters with 4V's too. look to the exhaust system vs overlap when choosing between a single/dual pattern cam with the Cleveland & 429/460

255DEH has 40* overlap, VERY little

265DEH has 55* overlap, very good for street perf, about the limit, may want a little converter?

275DEH has 60* overlap, maybe a hair too much, gonna want a converter & gears

for reference the 268H has 48* overlap, and i can tell you it WORKS in an otherwise bone stock 351C-2V / FMX & 2.75 with cast manifolds. it also stayed in the block when i swapped over to 4V Closed Chamber heads @ 10.25:1 and it still worked bigtime

here's a chart Luc John & his 16 year old daughter(Hahaha) worked up to show how overlap changes with Duration & Lobe Separation Angle
http://www.network54.com/Forum/119419/message/1349226140/OK%2C+have+chart

What about these?