360 Magnum building on an existing bottom end

65TTCuda said
Anyone have any experience with Speedmaster PCE281.1773 bare heads, 62cc chambers, 179 intake runners, setup for 1.92 intake valves 1.625 exhaust valves, 3 angle valve seat. They are reasonably priced for a budget build $339 a piece. I couldn't find any flow #s for these particular heads, but I have found for similar heads with similar intake runners, and those heads flowed at 260cc @ .500 - .550 lift. They are magnum style heads and I can build them up as the budget allows, that is why I'm favoring them. I have also looked at Edelbrock performer rpm heads but they are $700+ bare and $1100 complete. Can't justify spending that much just on heads alone, and I know the old saying "speed cost". But for a 60's street style gasser how much speed do you really need. Yeah it's fun to go to the track and make a some passes to brag what your car will run, but I don't have the budget to be competitive and break things. Besides there is always someone with more money and faster than you. So if you have any opinions or options concerning these heads please give them, I'm always open to any ideas that will help me make beast choices.

They don't flow great out of the box ..I think it was they peak around 220cfm. I have a thread on them here.
They are falsely advertised as well. These speed master magnums are not 179cc like they say...unless the valve is out and they fill the chamber too! I had left them a review... but they had removed it not once , but twice... and while I made a video CC'ing the port and sent it to them AND posted it on YouTube... they ignored it and said it didn't prove anything. They themselves would not offer up any proof that it was what they called it either.
In my opinion Speedmaster is a group of assholes who sell Chinese ****. None of it is any good out of the box ..and some of it is 'almost good' out of the box. The valve job is buried as in sunk in the chamber.They are also 150cc....which is somewhere around the stock port. Believe or not...they sent me TWO DIFFERENT CASTINGS as well. I had to return the one I didnt like for a match to the other I did. Wish I flowed the other head but I didnt. Imo it is better shaped ..but its like a fkn diamond in the sense you have to mine for it.

What I like to do because I don't like stock length valves and I want stainless and don't want to pay a bunch of money is I have the guides opened to 11/32...then a valve job for a set of 1.94/1.60 +.100 valves. Then I drop a 30,15, radius stone to dig out and blend the top valve job angles to the chamber. I then flip the head over and cut all the guides to .500 or .530 for positive seals..then I cut the spring pockets 1.44 and use a readily available valve spring and comp 740 retainers n super locks...Gasket match...blend the bowl and ssr... 260cfm with 1.94 intake valve...all that work enlarges the chamber...so then I mill them .020 to about 61cc measured and verified.
The intake port at the largest is 160cc by the time I'm done .

$1,200 is cheap for a set of brand new casting heads assembled flowing that suited to perform anymore. You used to able to get RHS heads for that or a hair less in some cases...but that all dried up.
You have the cost of the heads the cost of the valves the spring is the retainers all the stuff you need that actually works then you need some machine work or the ability and tools to do it yourself. If you don't have that give me a call and I'll take care of it and send you the bill. :)