I have the opportunity to pick up a set of complete newer heads for cheap. I know they flow better and have better springs, but what's the difference in the combustion chamber size? Will it change the compression? I was always leaning to get my stock heads ported ans new springs, but I can get these for under $100.

 

Buy them. Chamber volume spec is the same but all chambers will vary with manufacturing tolerances; typical is 85-86cs but I have seen them go to 89. Your compression won't change but, before you use them, it would be a good idea to have them gone over, new guide seals a good triple angle valve job, chambers ccd and perhaps, deck them a bit to increase compression along with installing them with a .030" head gasket. You will be surprised how much a bump in compression will help an otherwise stock or Stage I engine with a tune.

 

get them for sure,youll need the later intake flanges,but their cheap.good idea to have them gone thru,but dont bother with a 3 angle valve job (thats stock),go for a fully radiused SERDI valve job,flows leaps & bounds over a 3 or 5 angle valve job,and we just happen to use a SERDI 100!!

 

Thanks for the answers. Prodrag, I'd I went with the 1.9 port job you let me know about, is there any benefit of using the newer heads over the ones I have now? I have heard that the old heads had more material on them to shape them better and get better port velocity. Also, so you deck them during this to increase the compression a little? I was just wondering because I have to stick with a budget for now. Thanks.

 

No difference whatsoever between early/late castings, once port work is established, in particlarly, when you know the air flow you need, for a given engine combination.
Scott

 

Is there any benefit using the bone stock newer heads on a stock 88" with a cam only upgrade. I know you can only run a .510 lift on the old springs, but the new ones can handle like .575 or something like that. Can I then run a higher lift cam with .030 head gaskets to help bump the compression a little. I'm trying to justify I'd these heads are worth using over mine. I can't afford to do more than just the cams right now, but if I get these for $100 or less ans its worth it, I can spring for it. I hope to do a big bore and head work next year.

 

The advantage of the later model head is that it'll dump heat, and show a bit more hp, as the exhaust port is opened up from the Moco.
.030" head gask is fine.
Scott

 

Thanks Scott. Is there any added advantage of being able to run a higher lift cam? I know a few manufacturers make cams that have the similar duration and intake closing to a .510 or less cam but with more lift. Some range from .530-.580. If I looked at one of these cams, the newer heads and the .030 gasket, is it worth it over a standard bolt in cam with either stock or newer heads. Otherwise I may hold off and just get my heads worked on when I do the big bore down the road.

 

No real advantage to run higher than "bolt in" lift cams. Install the later heads, intake flanges required, with a .030" head gasket and Andrews 26 cams and forget the rest until you get ready for the big bore job.

 

Thanks. That's what I will probably do. Would the TW37 be a better cam? What do you think about the HQ0034 or the Wood TW-6. I don't mind to rev it a little, but I know the stock compression is limiting.