I snagged a set of 66 toronado "B" heads today. Large Valves. Came off a running 425 engine.

Wondered if there was any particular performance differences between these and the "E" heads i already have and was planning to use?

Difference in the way they will work with aftermarket cam & valve springs/etc?

The FAQ says E's have deep spring pockets & B's have shallow...


thoughts?

 

You may have to enlarge the push rod holes in the "B" heads. They are 45* heads as the "E's" are 39*. What block are you putting them on?

Gene

 

A 66 Toronado block should be a 39 degree block, but as Gene says, you may have to work the pushrod holes- esp if you're not 100% sure the engine came out of a Toro.

The deep spring pockets on the E's are for the new-for-70 "positive valve rotators". They didn't really affect performance one way or other. I think they were more in anticipation of non-leaded lower octane fuels that could have caused early valve seat failure due to no TEL to lubricate the valve seats.

 

I've got a '76 Fa 455 block that i'm building.. not numbers or anything, but it would be kind of cool to have the 66 "B" readily viewable on the side of the head since I have a 66.

They definitely came off a 66 toro 425 (I chucked the exhaust manifolds last night).

So basically no other real differences other than fixing the pushrod holes, and that they don't have the deep spring pockets for the valve rotators? (I probably wouldn't be putting rotators back in when i get new valves springs & stuff.

I'll get them torn down this week to check the guides & seats.

 

I'm taking it you already have the 455 machine work done and parts assembled, but if that 425 was a running engine, did you consider using it over the 455? Yeah, you have 30 more cubes, but a 425 is a formidable engine in its own right. You'd have an excellent start even if you did have to scrounge a set of .921 lifters.

 

I've never had to fix Toro 425 B heads for stock diameter 5/16" pushrods. If the E heads have the deep spring pockets you will need either rotators or different valve springs designed for about 1.88" height instead of 1.67". The factory offered thick spacers but you could end up losing valve spring positive location if the bottom of the spring is above the pocket.

 

Thanks joe- this is exactly what i needed to know- sounds like the "B"s are gonna be better just for ease of getting the right valve springs.