Diesel to gas reversion

[bigblockv6]

Originally Posted by bigblockv6

Myself, I would not waste time and money on the 305, just go with a bigger V6. I pulled the 305 out of my 68 K2500 and replaced it with a 478M V6. Putting a 3.86 stroke in a 305 will require custom pistons, the longer stroke will make the pistons travel slightly above the bore, some say you can have the stock pistons machined down. You want a stroker V6 GMC made a 379 from 1973-74, basically a 351 with a 478 crankshaft. Same thing with the 432, a 401 with a 478 crankshaft.

The 3.86 crankshaft has eight mounting bolts to the flywheel along with external balancing on the flywheel and front balancer, the 305 has six flywheel mounting bolts and is internally balanced. You would be putting way to much money into a 305 just to accomplish and extra 25-30 more cubic inches, just not worth it

[GMJakers13]

I appreciate the input. As far as cubic inches go it really doesnt matter. I understand its a different application but I built a few SBC stroker 305s and really liked the outcome. I like to play and build things just to see what happens, and was just curious. Now I need to find someone that knows about these PSJ injector pumps.

[LEWISMATKIN]

Hi gang! It's been a long time since I have posted on this group. As for the T/F, my deceased dad (Lewis Sr.) said he saw one dh478 converted back to gasoline, but their is a great deal of conversion to do to make it a gasser. And with such a weak crankshaft, why would anyone want to do a conversion?? T/F cranks cannot be cut to an undersize bearing unless the shaft were either chrome plated or rehardned. Anyway, it is good to see the group still up and running. Take care & God bless,

Lewis Ellis Matkin, Jr.
Ridge Manor, Fla
1965 1002 305e

[FetchMeAPepsi]

Originally Posted by LEWISMATKIN

Hi gang! It's been a long time since I have posted on this group. As for the T/F, my deceased dad (Lewis Sr.) said he saw one dh478 converted back to gasoline, but their is a great deal of conversion to do to make it a gasser. And with such a weak crankshaft, why would anyone want to do a conversion?? T/F cranks cannot be cut to an undersize bearing unless the shaft were either chrome plated or rehardned. Anyway, it is good to see the group still up and running. Take care & God bless,

Lewis Ellis Matkin, Jr.
Ridge Manor, Fla
1965 1002 305e

LEWISSSSSSS!

We were just wonderin about you a few months ago. Good to see you back!

[Ed Snyder]

Originally Posted by LEWISMATKIN

Hi gang! It's been a long time since I have posted on this group. As for the T/F, my deceased dad (Lewis Sr.) said he saw one dh478 converted back to gasoline, but their is a great deal of conversion to do to make it a gasser. And with such a weak crankshaft, why would anyone want to do a conversion?? T/F cranks cannot be cut to an undersize bearing unless the shaft were either chrome plated or rehardned. Anyway, it is good to see the group still up and running. Take care & God bless,

Lewis Ellis Matkin, Jr.
Ridge Manor, Fla
1965 1002 305e

Welcome back to the forum, Lewis! We've missed you and your expertise!

[LEWISMATKIN]

the problem with turbocharging a diesel engine is that the compression ratio must be lowered in order for the engine to operate without melting the pistons or bending the connecting rods. In the other GM diesel (series 71) the compression ratio went down from 21.5 to 1 to 17.5 to 1 and the connecting rods had to be changed because they were of a different material.

Cordially,
Lewis Ellis Matkin, Jr.
Ridge Manor, Florida
1965 1002 305E V6

[turbobill]

My DH478 has an advertised compression ratio of 17.5:1. Makes it plenty suitable for turbocharging.