1G G4CS Swap

[sleeper1ga]

So I'm interested in doing a 4g64 swap into my 1990 GSX, from what I understand the stock 5spd gsx trans will bolt up, however, I also heard that a 4g64 has the same motor mounts as a 7bolt 4g63. Does anyone make a mounting kit for this swap? Also is there any other factors that I should be aware of?
Thanks, Sleeper1ga

 

[synthetek]

You need a g4cs , it would have the correct motor mounts for a 1g.

 

[sleeper1ga]

What are the differences between a g4cs and a 4g64? Would I be able to run the same pistons/rods/crank etc?

 

[Kapok6]

Most 4g64 are 7 bolt with the exception of some very early ones like we're found in the expo. A g4cs is always going to be 6 bolt though. That's the extent of my knowledge on their differences.

 

[sleeper1ga]

Yeah that's about the same as my knowledge, I also know that the trans should bolt up to the block. My main question is whether or not the short block can run the same pistons/rods/crank as a 4g64

 

[Cox Abele]

The rod journals of the crank are wider on a 4gcs than they are of a 4g64. This is also reflected in the width of the big end of the connecting rods. Then, depending on your rod selection, your pistons may or may not work due to wrist pin size.

Build your motor from the crank up, not pistons down. I'm finding this out the hard way since I bought 22mm wrist pinned stroker-pistons on 1g rods which will not fit my 4g64 crank without machining of the rod's big end.

 

[sleeper1ga]

The rod journals of the crank are wider on a 4gcs than they are of a 4g64. This is also reflected in the width of the big end of the connecting rods. Then, depending on your rod selection, your pistons may or may not work due to wrist pin size.

Build your motor from the crank up, not pistons down. I'm finding this out the hard way since I bought 22mm wrist pinned stroker-pistons on 1g rods which will not fit my 4g64 crank without machining of the rod's big end.

Thanks for the advice, but will a g4cs be able to run a crank from a 4g64, and also is the cylinder bore the same?

 

[Cox Abele]

You will not be able to run a 4g64 crank in a g4cs block. That's the same as trying to stuff a 7-bolt 4g63 crank in a 6-bolt 4g63 block. Cylinder bore should be the same though. Depending on the block you use, pin placement and size will also be effected.

 

[sleeper1ga]

You will not be able to run a 4g64 crank in a g4cs block. That's the same as trying to stuff a 7-bolt 4g63 crank in a 6-bolt 4g63 block. Cylinder bore should be the same though. Depending on the block you use, pin placement and size will also be effected.

Thanks the reason I asked is that I know you can you use a 4g63 crank in a 4g64 and vice versa, along with the 4g63 heads(needs slight modifications).

 

[xaixiong]

The differences is the crank between both g4cs and 4g64.