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Advice on BBC Heads

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sapper92310

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Discussion starter · #1 ·
Mortec --> 14092359...86-90...oval...OPEN...366T, 427T, Marked "HiPerf"

I know they have small valves (like 2.08) and even though they're off a tall deck truck engine, they have oval not "round" ports.
I also know that all the other heads marked "HiPerf" that I've ever seen are Rect. Ports...so whats up with these?

Anyone know anything else about these heads?? I've searched ALL over the internet and found very little about them. I'm running them right now (freshly rebuilt) but I'd like to know if it's worth the time and money to switch to a set of 781's? Aluminum heads are very nice and I know they'd probably help out with a few HP but I'm broke as a joke and can't afford them :(

Car is: 74 Nova (Guessing ~3,400 - 3,600 lbs ?)
Engine is:
454 +.30
KB 257 Pistons (-25.5cc / .250") (11.04CR w/110cc Chambers 10.2 w/ 119cc)
Comp XE 284H (284/296 240/246@.050 .574/ .578 110 LSA)
Edelbrock Air Gap Intake
AED 750 HO Carb
2800 Stall TH350 w/ 4.10

Right now, I usually drive it between 2,600 and 6,200 Rpm I have no valve float and don't find that the engine is running outta steam BUT I think that maybe going to a set of 781's might be better than what I have right now. This was the first BBC that I've ever built and first one I ever drove so I really have nothing to compare the engine to.

Any help/suggestions/advice is appreciated
 
#3 ·
Any 1/4 mi. times on the current setup? That would be an indication of how well the 359's are performing. There's not alot of info currently available , performancewise, on those heads. :( Sorry. I saw a set recently, too, they looked comparable to other large oval, semi-closed chamber heads.

Rod
 
Discussion starter · #4 ·
No real track times yet :(

It kinda sucks that there's so little info on these...I have friends that are trying to tell me they don't breath right (over 5k) but I think they're confused with small round "truck" ports.

Some people say they flow exceptionally well, while others say they make good boat anchors...I don't really know what to think.
 
#7 ·
I'd keep running them and not think twice.
That combo should be in the mid/low 12's at around 108-110 MPH easily IMHO,even quicker with tuning and traction.
With that in mind,tuning the combo and gear/convertor selection is more important than anything.
Sounds like you need more convertor..something that flashes to 3500-3800
At least you have large ovals and very good compression with those pistons regardless of chamber size
 
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mr 4 speed
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