1275 head to 1000 block

[leebob]

hi having a sort out of my sheds i found an unleaded 1275 head.i was just wondering if i could bolt it to my moggy block and what,if any,advantages would be.thanks

[alainmoran]

Depends on the head ... it may have larger valves which would help your engine breathe more easily ... if your current head is working ok then you might consider stripping the spare head down, gas-flowing the exhaust ports & reconditioning it as you rebuild it.

You can then swap your existing head for one which you know is in mint condition (which can only be a good thing)

[bmcecosse]

I presume it is a 12G940 head ? If unleaded it will have the smaller inlet valve, but don't worry - it's still MUCH bigger than the normal Minor valves. You can fit it - but you must first carefully measure the distance from the top of the exhaust valve to the gasket surface of the head. You need 320 thou clearance. If it's any less - you need to sink the exhaust valves down into the head (up to 40 thou) to get 320 thou. Then you need a 1275 head gasket - and either a set of 1275 rockers, or carefully re-align the existing rockers on the shaft so they act DIRECTLY over the exhaust valve stems. You will likely also ned to file a bit off the top of the water pump to ensure clearance - and use a 'custom' top hose. The curved bit from a bottom hose works well! If the head doesn't have a bypass connection then you will need to plug the bypass on the water pump - or get a pump with no bypass. It will make the engine go very much better.

[leebob]

thanks lads,im trying to decide wether to take the modified route or standard route.is it just me or do we always think up something else just as we decide how we want it?