procomp big block chevy cylinder heads after 10 years on drag car see whats wrong!!

procomp big block chevy cylinder heads after 10 years on drag car see whats wrong!!

this is a look at a pair of pro comp / speedmaster 320 cc rectangle port bbc heads that were ran on a drag car for 10 years. they were used and abused by the owner. see what i found thats wrong with them.

video of car they were on

video was taken by youtube user cadpwr

subscribe link

help to translate link

canfield brodix afr procomp jegs summit patriot speedmaster flo-tek renegade revolution edelbrock holley dart world products blueprint rhs trick flow promaxx rect oval cylinder head review camaro


  1. hemi4sp on March 4, 2020 at 8:25 am

    lot of low lift flow be had by chopping down those UGLY MASSIVE MACHINIST RIDGES

  2. Jered Rice on March 4, 2020 at 8:25 am

    Looks more like a pushrod length issue to me..but I’m not the one working on it..

  3. scott Baker on March 4, 2020 at 8:26 am

    I can only run my 69 big block 375 chevelle on VP fuel. ..

  4. mick he on March 4, 2020 at 8:32 am

    dont believe them..its all chinese junk

  5. Backyard-Built-Trucks on March 4, 2020 at 8:39 am

    Look at it this way .if they were that bad they would not been used ten years . i know flotek , brodix and dart use a dedicated steel mold.

  6. Skyline Fever on March 4, 2020 at 8:39 am

    Sure, it might not makes sense to spend the money for new valves, seats, and guides for an as-cast Chinese head. However, if the porting was extensive, it might make sense to do all that stuff. I have seen videos of people going to extreme lengths to save damaged heads that were fully ported.

    A counter argument is that if you installed high quality guides, seats, and valves, you would get significantly more than 10 years out of those heads, making the who job worthwhile.

  7. Outsider25E on March 4, 2020 at 8:42 am

    10 years of drag use, I’d say I hardly see anything “wrong”
    per se.

    I’ve often heard about Pro Comp/Speedmaster heads being perfectly fine as long as they’re inspected by a reputable shop before being installed. The consensus being “Don’t buy them assembled, buy just the bare heads, have the shop double check the machining, then put the RIGHT valves, springs, etc in them.”

    I found this video doing research for my big block Ford restoration project. Not gonna be a race engine, so will probably go with something like this. Thanks.

  8. MegaScott on March 4, 2020 at 8:56 am

    10 years of abuse at the racetrack. They don’t look too bad. Lash caps would fix the cracking problems on the edge of the Valve stem. The early PC heads had problems with seats loosening, so your lucky. Considering they were cheap to start with, putting any time and money into an old set of Chinesium heads like this is a waste of money.
    Quality materials and machining cost money, this is where the Chinese cut corners to make a cheaper product. However, they are getting better as more and more American companies abandon making stuff in America in exchange for making a buck or two.

  9. mick he on March 4, 2020 at 8:57 am

    chinese junk..stay away…

  10. C Es on March 4, 2020 at 9:02 am

    Looks reusable. Change out the guides and machine in new seats and it should be good as new.

  11. Josr Fiscal on March 4, 2020 at 9:07 am

    Heads word good I have a set off 302 227 runners valves and guide were junk , I change everything to ferrea and comp cam components haven’t had a proem since

  12. Shit Box on March 4, 2020 at 9:08 am

    I’m amazed they lasted that long…

  13. TreasureSweeper on March 4, 2020 at 9:11 am

    Ive have a set of speedmaster 220cc on an sbc and immediately had guide issues on center exhaust ports, stuck an exhaust valve after 15 minutes run time. Heat stuck the exhaust valves on #4 & #6. Pulled them, replaced the guides and clearanced and haven’t had an issue since. I bought them bare and added my own choice of components. After 2 years they are still doing good in a street car..

  14. The1969ssx66 on March 4, 2020 at 9:14 am

    I bought these, ran sets with comp springs and manley valves. and they all still run great. I would rather spend 600$ for a bare set of these and add my own parts ! than buy 4,000$ heads that last the same or less.

  15. OldSkool 55F100 on March 4, 2020 at 9:15 am

    Was he running a mechanical roller cam? looks like they were out of lash….

  16. milan duic on March 4, 2020 at 9:21 am

    Engine reconditioner myself that’s pretty good for 10 years found with pro comp valve geometry is crap and guides are poor quality

  17. platoscave911 on March 4, 2020 at 9:22 am

    I calculating more or less around 1200 total miles with around 250 wide open throttle miles on these heads, hard to say if good buy or not but it seems heads were near catastrophic failure.

Leave a Comment