1977 4V engine

Hello everyone,
I'm brand new to the forum and have a couple of questions.
1. Just bought a complete 1977 460 4V engine out of an old LTD station wagon that the local yard had with 78,000 miles. I didn't notice until I got it home that it has a factory 4bbl carb on it. I didn't think a 4V was even available in 1977. Is there anything special about this engine being it is a 4V? I was gonna just toss the heads and intake because I thought it was a 2V. Haven't checked the block number yet because it needs to be cleaned off. I would assume it's an internal balanced engine being that the flex plate wasn't weighted at all. Is that a good assumption?


2. Like to build this engine to 521. Is the 4.300 stroke too long for the older blocks without the extra length in the cylinders at the bottom?

I have never seen a 2v 460. I have seen 2v 429s though. The 4.3 stroke will work fine in that block.

Yes internal balance. You will probably have to change to external balance. The block/ internal balance change was in '79. I too have never seen a 2bbl 460 only 429 and they are rarer than the 4bbl versions by far. The '74 and later engines were pretty doggy in stock form.

gt350hr wrote:  Yes internal balance. You will probably have to change to external balance. The block/ internal balance change was in '79. I too have never seen a 2bbl 460 only 429 and they are rarer than the 4bbl versions by far. The '74 and later engines were pretty doggy in stock form.

Me too.

Is there a specific reason as to why I would have to change to external balanced? I know it seems from my research that the external balanced stoker kits are cheaper?
Appreciate the responses.

I believe the reason behind the "switch to external balance" comment was based around difficulty in internally balancing a cast stroker crank when exceeding a 4.150 stroke.