383 conversion, outdrive concern.

[Galvez83]

Guys i am steps away from sending the 5.7 to be reworked and turned into a 383. I have question if the outdrive will sustain the new torque. My current outdrive is a DP-SM. Attached is the pic of the drive number. And another question would be how to determine if the 5.7 was really converted to a 383. Just being carefull with having some bad experiences with machine shops before. Thanks in advance.

 

[Bondo]

Guys i am steps away from sending the 5.7 to be reworked and turned into a 383. I have question if the outdrive will sustain the new torque. My current outdrive is a DP-SM. Attached is the pic of the drive number. And another question would be how to determine if the 5.7 was really converted to a 383. Just being carefull with having some bad experiences with machine shops before. Thanks in advance.

Ayuh,..... The DP-SM is a pretty stout drive, 'n unless abused, I believe you'll be happy with the package,......

Deal with a machine shop you can trust,.....
The stroke is a 1/4" longer, so no outside the block tell-tales,....

 

[Lou C]

That drive was used behind big blocks so it should be fine

 

[Scott Danforth]

The drive is stronger than a merc Bravo. You can even add a blower and the drive won't care

 

[Scott Danforth]

And another question would be how to determine if the 5.7 was really converted to a 383.

Measure stroke. Stock 350 is 3.48" stroke. 377 or 383 is 3.75" of stroke. 396 is 3.875" of stroke

 

[Galvez83]

I hear to look out for the block cranckshaft grinding clearance. Is there any truth to that?

 

[matt167]

I hear to look out for the block cranckshaft grinding clearance. Is there any truth to that?

Some. Many 383 cranks can be set up without clearance, and then you can use either 400 rods or aftermarket 5.7” rods which are machined or cast to clear the cam

 

[Scott Danforth]

I hear to look out for the block cranckshaft grinding clearance. Is there any truth to that?

yes, the block must be clearanced along the pan rail. you can buy the blocks pre-clearanced for an extra $100 or you can take 20 minutes with a die grinder and clearance the pan rail.

unless its a dart block or world product block, all production GM blocks must be clearanced for a stroker crank.

 

[QBhoy]

These things and their predecessors similar have been surviving big blocks and torque plenty diesels for a good while now. Certainly over here they and the earlier 290 dp have been mated to plenty big power engines, driving heavy and serious boats like princesses, sun seekers, fairlines, windy and all the rest of them. They are well engineered and robust things I think. Pain in the arse to remove and put back on compared to a mercruiser for sure. But ok if they’ve been frequently seen to, as they should be.