New Engine-What size balancer?

[Slonaker]

I am about to order a crate motor from Summit. It says it comes with timing tabs for both sizes of balancer. What should I get?

I'm not sure what size the original 305 has. I'm not re-using the balancer. It has a groove worn in it, and so does the sleeve a previous owner put on it. I tried to measure it last night, but I could not get close enough to it without jacking the truck up, and it was late and COLD.

Will my stock pulley fit regardless of size, or do I need to match what is already on there?

Summit lists a 6 3/4 in their "suggested parts" section, but does not say why.

Thanks,

Slonaker

[crawdad]

My truck is at the body shop right now having the frame aligned or I would run out there and measure it for you. If memory serves me correctly (and its been failing me here lately ), I believe the balancer on my 305 is somewhere around 6 3/4 inches. I'm guessing so don't hold me to that however.
ADDED: Just out of curiosity I looked on the GM web site at their crate motors and engine parts. I noticed that they recommend the 6 3/4 inch balancer for the 305 and 350 engines. The 8 inch balancer is used primarily in racing applications. Beyond that I don't know why they would recommend one over the other.

[Slonaker]

Thanks. That's good to know.

Slonaker

[piecesparts]

Aftermarket balancers come in all sizes. I have had both on a 350 motor and had no problems. I presently have a 6 3/4 balancer on the 383 stroker motor and it works fine. the last stroker had a larger Fluiddampener on it.

[SlapFish]

I'd guess, going by basic physics, the bigger the better if it has a lot of power. If it's going to be running fast or hard, get a bigger one.

[fastwillie 696969]

get the 8 inch dampfluid balancer

[fastwillie 696969]

http://shop.enginekits.com/osb/itemdetails.cfm?ID=353 check this place out

[jimfulco]

Check www.ebaymotors.com for ZZ4 balancers. There have been some new take-off balancers on there in the $50 range recently, and the ZZ4 units are 8" diameter and have degree marks etched in them.

[Slonaker]

Sorry I missed the responses from the last of you guys. I ordered the parts early this evening.

I ordered a Goodwrench 260 hp 4 bolt main 350, a Summit branded stock 6.75inch balancer, a Summit branded SFI approved flexplate, a Mallory HEI, a set of Moroso wire looms to route the plug wires under my exhaust manifolds, and the necessary gaskets to put everything together.

Kind of scary spending this much money. I told my wife I have never spent this much money at one time without getting a whole truck or a house or something out of it.

Thanks for the info, everyone.

Slonaker

[SSC's76]

A 350 comes from the factory with an 8in dampener. A 6in (305) dampener reduces rotating mass and is supposed to let it rev a tad better. It doesent really matter as long as the timing tab is aligned correctly. a GM stock performance upgrade on the cheap would be any TPI Z28/TA dampener.