Can a 1275 Cylinder Head be put on a 1970"s(not sure how to tell year) 998 block? Have duel carbs to put on head as well. I was told if doing this to replace a gear in tranny for higher top gear? one more tooth? Also, How much would you pay for a used 1275 head complete, needs TLC. Thanks

 

sorry no not without making pockets for valves in block........

 

you would be better spending money on a stage 3 or 4 head for a998cc

 

Thanks for the info.

 

If you want taller gears in the differential, you need to change the pinion and crownwheel both - of course, if you don't change the speedo gears too then your speedometer will be off.


Sometimes you have to modify the pinion gear bearing retainer too, so the larger pinion will fit.


How far you go will depend on your goals - quieter running, higher top speed or so on.


I went from 3:44's to 2:76's, I think next time I'd go with 3.0......

 

How much would you pay for a used 1275 head complete, needs TLC. Thanks

You need to find someone who needs or wants one ...... isn't that E-Bay's thing?

but you could watch Seven's site as they have items like this on their used parts list from time to time . . .

 

Absolutely you can put a 1275 head on a 998 block and yes you can do it without pocketing the block if you are using a stock camshaft and stock lift rockers. With a performance cam, you may need to pocket the block or use a head that has valves that are flush with the head chamber =I have done it many, many times. It is a very worthwhile endeavor and is essentially like putting on a 12G295 cooper head that's been skimmed. You will need to use a 1275 head gasket.

It will raise your compression, so best if you not do it with flat top 998 pistons, but dished pistons are fine and you can still run premium pump gas. It will rev a lot more freely than a stock small-valve, non-cooper small bore head. You will need to check that you have clearance for the water pump pulley if you are using a large diameter style. You can grind the bottom of the thermostat area of the head for clearance.

There is one water jacket hole that may or may not be partially obscured by the head gasket (depends on which 1275 head gasket you use). Pic here http://www.hubgarage.com/mygarage/Sp...photos/1440733

If you go back to that gallery (above) and look at the pics and captions, I show how I pocketed the block myself because I was using a performance cam on that build. But, again, it is not necessary if you are using a stock cam and a less-than-fresh head. If the 1275 head you are using has new exhaust valves and new pressed-in hardened seats and the valves are protruding far into the head chamber, then Yea, you may have an interference problem potential on your hands. But a used head with a quick valve job or lapping in of the valves, you're fine.

I took comparison pics of a "cooper" head and a 1275 head. Same port sizes but a 1275 head is loads cheaper and more available
http://www.hubgarage.com/mygarage/Spank/vehicles/65193