1986 454, Square or Oval Port Head?
 

Got a Chance to buy a Edelbrock Manifold for a BBC, Seller stated it's for a Square Port Head. What Head Type will my Stock 86 454 Engine Have & Does it Make a Difference???

Thanks, Rick

Re: 1986 454, Square or Oval Port Head?
 

86 should have been peanut port head which is a small oval port head . The square port intake is for the early high performance heads that had square (rectangle) ports . I think that intake would do more harm than good on your truck .
Frank

Re: 1986 454, Square or Oval Port Head?
 

Your 86 should be oval port.. although some had the "peanut ports"..
The square port intake will work on yours as long as you use square port intake gaskets.. (otherwise you will have a big vacuum leak!!)
Using that intake wont hurt but you will not really gain anything other than having an aluminum intake.

Re: 1986 454, Square or Oval Port Head?
 

Thanks for the Quick Responce, I was'nt sure which i had or if it would make any Difference................

Price is Really Good at $20.00, Just wanted to know if it was a worthwhile investment.

Thanks Again, Rick

Re: 1986 454, Square or Oval Port Head?
 

buy it and peddle it

Re: 1986 454, Square or Oval Port Head?
 

I would not even try to use it....It will definately hurt performance and throw your fuel economy in the toilet.
The huge runner volume if the rectangular port manifold will kill the velocity of the incoming air/fuel charge. This results in low vacuum signals to the carburetor...poor throttle response, bad mileage. Then the air/fuel runs into the nasty edge of the smaller port in the heads, this results in what is called "fuel dropout". Fuel dropout is exacly what is sounds like, the fuel drops out of the air, resulting in poor burning...loss of power, stumbling, etc.

Not good.

Re: 1986 454, Square or Oval Port Head?
 

Longhair forgot to mention oil dilution as also being a problem. You could get yourself a set of "open chamber heads" with 2.5" intake valves and 2" exhaust valves. Then you could use the intake, LOL. You'll hurt MPG though. I built one back in the 70's. All the goodies.600 horse at the rear wheels! Pick the front end of a 69 Chevelle 3 feet in the air w\14" wide slicks. Best track time was 9.9 sec at 148 MPH. Rear was a Brown spool and trans was a close ratio Muncie w\a vertigate shifter. A PITA to drive and really tough to get around corners, LOL. Wish I was that young and dumb again. Want a beasty? I'll build you one. jim

Re: 1986 454, Square or Oval Port Head?
 

That's what the "etc." was for....LOL

Yes, you could swap the heads to match, but then you would need more compression to make that work too, then come the pistons...... So it's a whole new engine to go under that cheap intake...

Re: 1986 454, Square or Oval Port Head?
 

Buy it, sell it and buy the correct one for your heads. Pull a valve cover and get the 6 or 7 digit casting number and post it back here. I'm betting the casting numbers end in 236 which is peanut ports. The Edelbrock Performer intake will fit those. If you have 781 or 049 castings, the Performer RPM or air gap will work. I wouldn't even try the big square port intake on smaller heads for the above mentioned reasons. It's actually worth more than the small port intakes, you should be able to sell it for enough to buy the correct one.