Question about the 305 engine.

[BobClvrt]

I have an 81 K 10 with a 305 and I need a new block. Does anyone know what years I can use for the block replacement? Since I'll be using the old heads and intake can I use a block from a newer vehicle or will the dimensions be different?

 

[Soundmound]

Sorry I can't answer your question, but now I have my own. Why? If it were me and I was block deep, I'd be replacing it with 350 cubic inches or better.

 

[mshawn]

Any two piece rear main seal v8 block will work. I would short block a 350 cid myself and use the heads and intake , then over time change heads out to a higher performance head and then aluminum intake . Slow build over time. Technically you could use the 1 piece rear main seal blocks from 87( mid 86) up to 92 if you do it right

 

[BobClvrt]

Truck came with an engine rebuild kit when I bought it. I'm not really an engine guy, I'm more suspension, so basically any decade 305 block should work or are you saying most any V8 small block will work? I'm not keeping the truck, I got a good deal from a friend and I'm doing the work with my son to show him how to work on cars before I sell it, the truck came with a bed full of parts

 

[Bennyt]

Truck came with an engine rebuild kit when I bought it. I'm not really an engine guy, I'm more suspension, so basically any decade 305 block should work or are you saying most any V8 small block will work? I'm not keeping the truck, I got a good deal from a friend and I'm doing the work with my son to show him how to work on cars before I sell it, the truck came with a bed full of parts

What's wrong with existing block?

Trying to find a block that matches what you already have might be difficult. You might be further ahead in time and finances selling what you've got and buying a cheap, running 350 and just doing a rering and bearing kit.

 

[AyWoSch Motors]

Truck came with an engine rebuild kit when I bought it. I'm not really an engine guy, I'm more suspension, so basically any decade 305 block should work or are you saying most any V8 small block will work? I'm not keeping the truck, I got a good deal from a friend and I'm doing the work with my son to show him how to work on cars before I sell it, the truck came with a bed full of parts

Any Small block chevy short block will work with the heads you have. As far as I know any SBC heads will bolt up to any SBC block. From the '55- 265, to a '98 350, they all have the same bolt pattern.

I'd say if your block is healthy, rebuild what you have, but if you have a major issue with it, any old small block will work. I'd suggest dont get another 305 if you can help it, unless it's good and dirt cheap. I'd suggest try for a 350 short block, and use your heads. 305 heads are pretty good.
Or if you can get a running long block, thatd be even better.

 

[Rusty Nail]

The oil seal changed in 86, so did the oil pan. The cylinder heads will bolt on but changing rear main seal is NOT a direct swap. of. all. parts, be advised.

Rebuild what you have OR buy a different PRE-86 block to keep costs low.

Good luck!