305 Block Question

[classicxl]

last week i was talking to a guy about trucks when i told him my truck has a 305 in it.the guy then said the only problem with the 305 is that the block likes to crack because gm bored the Cylinder holes too big.leaving the sides very thin so get ready for yours to crack is this true these blocks crack alot

[wayneo]

last week i was talking to a guy about trucks when i told him my truck has a 305 in it.the guy then said the only problem with the 305 is that the block likes to crack because gm bored the Cylinder holes too big.leaving the sides very thin so get ready for yours to crack is this true these blocks crack alot

That guy is full of crap.

[Graya25]

last week i was talking to a guy about trucks when i told him my truck has a 305 in it.the guy then said the only problem with the 305 is that the block likes to crack because gm bored the Cylinder holes too big.leaving the sides very thin so get ready for yours to crack is this true these blocks crack alot

That guy is full of crap.

 

 

Agreed. My 305 in my 1997 has had no problems in its 12 years, so I find that quite hard to believe.....

[Kevin_J]

I've never had a 305 but think of it this way. A tried and true 350 SBC has a 4" bore and a 3.48" stroke. A 305 SBC has the 3.48" stroke yet a smaller 3.736" bore. There should be plenty of meat in that block. In my opinion they bored out those blocks too small

[59ih340]

There was some sort of a problem, around '87?ish? I remember a couple people with full size Blazers getting them warranty replaced.but I think it was a short time and not really many vehicles total

[SilveradoWV]

I would think it would be a casting problem not a design problem if there is a problem at all...

[Kevin_J]

I would think it would be a casting problem not a design problem if there is a problem at all...

 

Thats what I was thinking. Maybe it was a Henco En Mexico casting. I used an old Targetmaster block for a build once and ended up cracking it at the main webbing.

[HarlanC]

My parents have an article of a guy who owned a Sierra with the 305 in it. He got it up to 1,000,000 km's and it was still running perfectly fine. As far as I know these are the best engines known to man =P I may have a biased opinion cause that's what is in my truck haha

[Zembonez]

305s weren't ever a problem. Some engine builders disliked the small block 400 for the reasons the OP posted. The space between the cylinders was pretty thin on them. 305s have plenty of metal in them. Lots of people didn't like the 305 because it wasn't known for making much power.

[txab]

last week i was talking to a guy about trucks when i told him my truck has a 305 in it.the guy then said the only problem with the 305 is that the block likes to crack because gm bored the Cylinder holes too big.leaving the sides very thin so get ready for yours to crack is this true these blocks crack alot

 

Someone should beat that guy with rubber hose........

[MCourson]

305s weren't ever a problem. Some engine builders disliked the small block 400 for the reasons the OP posted. The space between the cylinders was pretty thin on them. 305s have plenty of metal in them. Lots of people didn't like the 305 because it wasn't known for making much power.

 

Agree 100%, they don't make much power but they can last. See my sig for proof.

[Telco Tech]

It depends on who you talk to. I was one who had a cracked 305 block. You shouldn't dismiss the comments you here so readily. I bought my '89 new with a 305. It always ran hot and I figured that's the way all the new engines ran. After about 30K miles I checked my oil and the level was high (?). I pulled the oil cap and there was brown goo/ jello in the top of the heads. To shorten the story; the dealer mechanic replaced the short block only and bolted all the original parts (without a good cleaning) back on the engine. I had clouds of white smoke on startup. I gave up on that particular dealer and bought a crate 350 over the counter at a another dealer and installed it myself in Jan. '94. That 350 still runs great and I'm still driving my truck. The dealer had admitted they had to replace a couple of engines in those years. When they fail it's generally early in the engines life, I would say. If you've got a 305 with high miles then you wound up with a good one. If I had a choice I'd stay with a 350.

(Oh yeah, the 305 engine block was cracked in the lifter valley...)

[classicxl]

the truck is a 96 with the vortec 5.0, so i am guessing if there was a problem in the early years it should be fixed by 96 right. Trucks has 228.000km and runs like new.by the way i just bought marker lights for my cabs roof can't to see them on my truck.