425 heads on a 472???

[sizanjdf]

Ive heard of putting them on a 500, but was wondering what it would do on a 472...I want to get about 350-400hp out of this engine as cheap as possible. I figured raising the compressing, cam, intake and carb would probably do it. does this sound like a good plan to you guys?

[lux hauler]

It'll work but all it's going to do is raise the compression.....the engine won't breath well at higher RPMs.
If you're looking for inexpensive, low RPM power, and have a good set of 425 heads....I say go for it. If you have to put money in the heads, don't waste your time......My $.02.

[dave_brode]

sizanjdf,

425 heads will raise compression on the 74 model year 472 only, which has 120cc heads. They would lower the CR on the older 472, which have 76cc.
Dave



"]Ive heard of putting them on a 500, but was wondering what it would do on a 472...I want to get about 350-400hp out of this engine as cheap as possible. I figured raising the compressing, cam, intake and carb would probably do it. does this sound like a good plan to you guys?[/quote]

[sizanjdf]

what did they do different in 71 from 70 to lower compression on the 472

[dave_brode]

sizanjdf,
Different pistons. If your bores are nice, you might ask around for a set of '68-'70 pistons for your 472. Or, bite the bullet and get a set of KBs.
Dave



"]what did they do different in 71 from 70 to lower compression on the 472[/quote]

[STDog]

sizanjdf,
Different pistons. If your bores are nice, you might ask around for a set of '68-'70 pistons for your 472. Or, bite the bullet and get a set of KBs.


Or you can buy the set of '74 rods and pistons I have :)

If interested I'll get the sizes for you and some pic.

[lux hauler]

sizanjdf,

425 heads will raise compression on the 74 model year 472 only, which has 120cc heads. They would lower the CR on the older 472, which have 76cc.
Dave
Thanks for making that clear, Dave.