Seen one of these for sale. Never seen one for the 351m/400. 4bbl manifold with the ports being split. Curious how it performs compared to a Weiand or Edelbrock.

 

but guess i could explain them just in case

they are suppose to give better bottom end(match for my app)

good/better economy(ditto)

rated to 5000 rpm 5500(maybe more) with alittle mod trim 3/4 inch off the end of the divider near head and open the divider between the secondaries makeing a slightly bigger oval instead of 2 holes (sounds good ,too)

the primaries are isolated and sent thru the smaller/ hi-velosity runner to all eight ports giving good tourque, responce, and econo

the secondaries are send thru longer bigger bottom runners to all eight ports

they appear heavier than edlebrocks/weiland so i figure less warpage, or chance of since they are dry and not cooled

also if you think of it if you are runnig for tourque with the primary only open you have the secondary port under it acting like(is) a dead air space i figure it would keep the primary cooler

this as of yet is only reading reports as my aussie heads need to be cut yet
still got to get this done and now i need a new carb
the one i got for 50 bucks ends up a 750cfm and while i can put smaller jets in, but still too much carb

but comin up is a aussie on stock 351m 2.19/1.71 undercut swirl polished roller tip 4340 rockers crane conversion(yet to buy)
at 35 for regular 7/16 studs(85 for the proper clevland studs) 25+ for guideplates 60-80 for hard push rods plus machine work
and crane conversions are 85????? stock rods are ok no machine work daaaaa

, offy 360(no mod(well), just polish), and a 600-650 cfm eldebrock tuned on a 1 inch parabolic

watch this i am gonna pressureize my crankcase with blow-by and blow my dip-stick out i know its coming but i hope not

thinking since it's not well sealed now i figure 100 horse anyway

later i think i want a 265 or 275 deh compcam with hi-tek(or if need be rhodes) rapid bleed lifters and intake/ head porting thinking bout opening the bottom port on the offy a little and match on the head

am i running on again??

 

I figured that was the purpose on split ports, one for primary and one for secondary. Alot of new vehicles have that setup in their intake, with a valve to control them. Question is, does it really work? Does it produce a noticeable difference over a Weiand or edelbrock?

 

well could swap just the intake and carb on mine to see


as long as you aint expecting record breaking top-end

 

Saw the DP offy on ebay specifically for a 351/400m, rare number.
The one for the cleveland i believe is 6011-dp (requires spacers for the M crowd).
This ones # was something like 6033 dual port. I was about to buy it but some lucky scooped it quick...

 

available new from any offy dealer but they have no web precence

i have the PAW catalog in front of me(a dealer)
for some reason they have 2 for the "m block"
off-6013-dp 351c 4v(bbl) heads.......................238.95
off-6110-dp 351c 2v..........................................254.95
off-6141-dp 351m 75 and later,std. 4bbl carb 254.95
off-6033-dp small port 400 clevland 1971 and
later std 4bbl carb.................254.95

whats rare about them just because evebody just blows them off b'case they aren't edlebrock or holley

now the port-sonic/turbo-thrust/small chebbie low profile ram(sweet looking)/many more in catalog more than a dozen designs
including 3x2 are not available for the m-block

as for useing a spacer, paw got one from weiland for 129.95 over 20 dollars(slightly included shipping) than the used dual port i got off ebay

well anyway