need help

[truckdude239]

okay so i ended up buy a remanded 350 4bolt main from advance auto for 960 buxs the guy installing it will not install it unless i get a new flywheel he says that the flywheel on my 307 is different from the ones that go on the 350 and says that my 307 start will not start a 350 i think different. some please confirm that my parts will bolt up

[sdkid]

According to napaonline dot com, they take the same flywheel. I think most sm chev are the same. You'll need to find out what the specific problem is with the old one.

[truckdude239]

all he says is it is a different style i the motor i ordered was for a 1971 c-10 with 350 4 barrel with 4 bolt main i was looking at advance auto and it also shows same flywheel and same starter guess i will show himt his in morning

[dwaite72lnghrn]

Are you sure you didn't get a 350 with a 1 piece rear seal? The crank flange is different on them. Other than that I thought they were the same.

[jsbgump]

As long as it is not a 1 piece rear main seal motor, the flywheel and starter will be the same.

[mrein3]

In 1989 I rebuilt a 350 out of a mid-70's Monte and put it in place of my 1972 Chevelle's 307.

I was working at a shop back then so I had access to a hoist where I did all the work.

So I get EVERYTHING hooked up. I check everything twice as this was my first project like this solo.

I put the car down on the ground and hit the key -
All I heard whas the starter moter spinning freely.

Yep. The 307 flywheel was smaller in diameter that what I needed.

A trip to Midway Chev and $50 later I had that engine running with a brand new GM flywheel on the back of it.

[Chris H]

If I understand things correctly, there are only 2 flexplates available for the small block chevy engine with 2 piece rear main seal:
A 153 tooth (12.75") and a 168 tooth (14"). The 400 small block motors have a unique counterweighted flexplate, and I am ignoring those for this.

I think the starter is different depending on which motor is used, and as long as both the starter and flexplate from your 307 are used on your 350, you should be good to go.

A quote from Sallee Chevrolet website: "The starter must be matched to the flywheel or flexplate diameter when installing the Premium ZZ383/425 engine. Small diameter flywheels are 12-3/4” and have 153 teeth. Large diameter flywheels are 14” and have 168 teeth. This difference in flywheel diameter requires two different starter housings. Starter noses used with 14” diameter flywheels have two offset bolt holes; starters used with 12-3/4” flywheels have bolt holes that are straight across from each other."

[truckdude239]

when i looked up the 71 c-10 with 350 it calls for the same flywheel as the 307 the 168 tooth flywheel i guess i will get him to try anyway