ProComp Boss 429 Heads

[EDrgr]

It was bound to happen. Has anyone seen these in person yet? Thoughts/ opinions?

https://www.ebay.com/itm/Ford-429-460-B ... SwgFJa8~DF

[blykins]

For $1500 each, I'd rather buy from Jon.

Actually, if these were $15 each, I'd rather buy from Jon.

Procomp has its own reputation.

[SupStk]

Interesting! I wished they posted pics of the runners and chamber. Wouldn't have thought those heads to be a high demand item. Hats off too them for giving it a whirl.

Rather trust Kaase for a build that's going end up being high ticket.

[EDrgr]

Yep, I agree about getting a pair from Kaase. At least you know what your purchasing. There is no telling the quality of the PC Boss heads.

[Ron E]

Don't forget C&C motorsports. They make everything for a Boss. Very good quality.

[Paul Kane]

It was bound to happen. Has anyone seen these in person yet? Thoughts/ opinions?

To answer your question objectively: Yes, I have seen them in person, a bare set, had them on the work bench and looked them over closely. They are very nice looking heads, the machining looks good on the set I inspected, the aluminum material and casting quality seem good, etc.

They look to me as though a CNC'd Kaase head was purchased, was digitized, and then duplicated--for example, the valve seat ID transitions smoothly to the valve bowl casting very well just as cast and machined (ie, little-to-no bowl blending needed to remove a "step" in the transition). I did not do any dimensional inspecting because with this particular set of heads intended application they are going to be significantly modified before being put to use anyway, just as would would be necessary with the Kaase Boss 9 heads under the same circumstances. Please note this has to do specifically with our intended use of the heads outside of their inherent capability and not a downplay on the heads themselves.

Procomp also offer Boss 9 rocker arms, and those look nice, too, although I did not disassemble them and look at the bearings, or do any destructive testing. By the way, the rockers look like a knock-off of a major Boss 9 rocker manufacturer as well. At this time there are no Boss 9 valve covers being produced by Procomp but I think that will change shortly.

My initial impression is that the Boss 9 Procomp heads will suit the needs of those common enthusiasts who are seeking the typical capabilities of what a 1969 era Boss head can support. That being said, they don't offer anything over the Kaase heads and ironically they have the same limitations duplicated right into them, specifically in the area of valve spring diameters, valve spring installed heights, overall valve lengths etc. In all fairness, for our project we should really be working with A441s which is why we keep encountering "necessary" mods. Incidentally, the exhaust valve seats look to be about 0.375" tall and I wish they were 0.500-0.625". We'll tilt the can anyway, and if the seats loosen then we'll install deeper ones. But for most typical enthusiast applications they will remain an alternative as much as other early-style Boss head producers of which there are at least a couple if not more.

[EDrgr]

Thanks Paul. Great write up.

[canada1]

A pair of bare procomp boss429 heads are $3,000.00
A pair of Kaase Boss 429 heads bare are $3,600.00
$600.00 well spent.

By the time you replace the valve seats and valve guides in the pro comp heads you are spending more than the cost difference.

[Keith Morganstein]

I wouldn’t think there was enough demand for a copy. Maybe “speed master” thinks their direct marketing will sell a bunch?

How much is the total cost of installing and setting up boss nine heads on a 385? All parts including valves, springs, rockers, pushrods, manifolds, headers and valve covers? What technical difficulties are encountered?

It would seem $600 is fraction of the total cost, maybe ten percent?

[DCal]

I thought that they showed quite a bit of core shift around head bolt bosses, push rod holes and valve spring pads, they may prove to be too thin for anyone wanting to do port mods. For mild performance they are probably adequate though.