I have an A87 head I'm thinking about slapping on my 71 510, and I was wondering, is enlarging the intake ports to 1.50" the only step required(outside of a different cam) to pretty much making it into the same thing as a V912(SSS) head? If not, what else do I need to do? Also, this is going on an L20B. I don't have the Z22 crank in it. I don't have dual sidedrafts, and am debating whether or not to seek some out. Right now I'm running a 32/36 downdraft weber. Would anybody recommend against this type of head modification? If not, then is it going to be foolish for me to continue running my 32/36 if I decide to do the porting? It's got a W58 smog head on it right now(blech), and while it IS making power, i want MORE. Thanks.

first...is the A87 a peanut head? You would not have an SSS equivelent if it is not.

Porting is not a bad idea..if you have a larger intake to match it too. Take your time and do it right.

Second...the W58 head may be a peanut head. So with the larger ports and the smaller chamber you would be getting good power out of it. As for the exhaust liners, I would, when you have the head off, pull the exhaust valves and yank out those liners and polish the ports.

The W58 peanut head is what I have and I love it!! Now, before you ask.....the only way I can tell you how to check if your W58 is a peanut or not is to pull it off the block.

The Weber 32/36 is the way to go in my book, unless you want two like I have. Side drafts are nice, but expensive and harder to tune.

I hope this helps.

The A87 is a peanut head. Now, I recently came up on the old edition of "How to Modify Datsun Engines & Chassis". According to that book, the A87 as it stands is in fact, SSS equivalent. I was under the impression that the A87 was the SSS only w/ smaller intake ports(1.25" rather than 1.5")... is that not true?I was practically gifted a set of dual mikunis & intake($100). The intake is 1.5". Do you know much about these carbs? I think they may be the 44mm, but they're pretty big. If they're the 50mm, I don't really feel like they'd be efficient for running what I'm tryin' to do. I don't want to go the distance to try and make the head an FIA. The W58 could be a peanut head also? If it is, then it's possible to yank the exhaust shields out without damaging the head?Thank you, I appreciate your input.

MicroMachinery wrote:The A87 is a peanut head. Now, I recently came up on the old edition of "How to Modify Datsun Engines & Chassis". According to that book, the A87 as it stands is in fact, SSS equivalent. I was under the impression that the A87 was the SSS only w/ smaller intake ports(1.25" rather than 1.5")... is that not true?I was practically gifted a set of dual mikunis & intake($100). The intake is 1.5". Do you know much about these carbs? I think they may be the 44mm, but they're pretty big. If they're the 50mm, I don't really feel like they'd be efficient for running what I'm tryin' to do. I don't want to go the distance to try and make the head an FIA. The W58 could be a peanut head also? If it is, then it's possible to yank the exhaust shields out without damaging the head?Thank you, I appreciate your input.

I don't know much about the Mikunis...except they are sweet!! lol

You are correct about the A87 head if it is a peanut head....it is the same axcept the ports are smaller. So just port em out and call it good.

The W58...you can yank out the liners. But you must pull the exhaust valves first and take your time with them. I have not done this yet, so I am not aware of any snags.

If you do it, would you let me know how it goes?

Right on.

And about the W58, I'll let you know. If it's the same story(peanut chamber), I may just use that one instead of the A87, since the cam towers are already on it... assuming I can get the exhaust ports opened up.

There is some contraversy about the liners...some say they inhibit your performance and some say they don't have any effect at all.

So do some research before you go through all that work.