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At what point to replace pistons?

ChrisPerry said:
I wouldn't put a 305 in a truck even if it was free. 350 = more hp, tq, and more mpg. It's a no brainer to me.
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He would need a new knock sensor, ESC(?), injectors(?), and PROM, at least of what I can remember. Not that the injectors wouldn't be a good idea to replace at the same time, but just considerations. As common as TBi 350 R/V parts are still, it shouldn't cost too much, or be too hard, to swap to the 350. If it can be done relatively inexpensively, I would concur. The cost to rebuild or purchase a crate 305 is probably the same, if not more, than a 350.
 
Yep, the 307 was before the 305. The 267 was a car motor.
 
the 265-cubic-inch (4.3-liter) “Turbo-Fire” engine arrived in 1955 as an option for the Bel Air and Corvette.
 
All my Chevy motors came for GM Black. My 305 in my boat. 350 in my blazer and last of factory 7.4 liter in my motor home.
 
nvrenuf said:
The only reason a 305 isn't the worst V8 GM made is because the 267 exists. :rotfl:
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Don't forget the 262 V8 they put in Chevy Monza's..those were not the greatest V8 either,but at least a car with one could be upgraded to any other SBC without much trouble..

I had a 267 in an '80 El-Camino "Royal Knight" ,and that engine ran smooth as silk and it cruised at 80 mph effortlessly..it also had a 2:56 posi diff,which killed any hopes of laying rubber unless you started off on sand or ice,but once you wound it up some it went right along..vehicle did not weigh much though..

I put one in place of a 250 six in a friends '82 C-10,which came with a rare factory 5 speed,tranny was the same one they used in Monza's,it was a telephone company fleet truck originally..we swapped a TH350 in it too..it seemed to go pretty good,it had fairly low gearing,anything was better than the camel humper six that was tired..

I had only one 305 ,I got from an '86 G-10 van and put in my '79 C-10 "Bonanza" in place of its original 250 six,another 2 bbl camel humper that spark knocked so long it wiped out the #6 piston..
The 305 had the same stroke as a 350,just smaller bore,so they had more low end than the smaller V8's..

I've had at least 4 of the 307's in various trucks and cars and I always felt they got a bad rap,the cam lobes going flat gave them a bad reputation,but once a new cam was put in one they ran as well as any of the other small blocks--the shorter stroke they had (and the 283 & 327's) made for sluggish take offs unless you had low gearing,but they will wind out like a chain saw once you get them spinning over 2500 rpms..

When I worked at a parts store with a machine shop,many customers decided to buy a "Target Master" or "Mr.Goodwrench" new engine after getting all the costs added up for a complete rebuild of their old engine...it was cheaper in most cases,had a warranty,and the end results were usually more satisfactory..we had a few engines we rebuilt go sour not long after,(like a cylinder cracking,etc)--and we offered no warranty,it caused a lot of hard feelings in some cases..

A few customers did have issues with the new engines though,including one that rapped instantly upon start up..the rod bolts were left loose on one connecting rod!..:doah:..back then those factory replacement engines were "Hencho En Mexico" and some were not put together well..
 
diesel4me said:
A few customers did have issues with the new engines though,including one that rapped instantly upon start up..the rod bolts were left loose on one connecting rod!..:doah:..back then those factory replacement engines were "Hencho En Mexico" and some were not put together well..
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Believe my crate L31 came from Mexico. They probably cast them down there, on top of just assemble...I wouldn't be surprised if environmental/safety manufacturing costs are a lot cheaper south of the border.
 
What I heard back then was Mexico had no real "emission" laws regarding metal foundries ,so yes,it was cheaper to have them made there,along with cheap labor costs..

I read once in a Hot Rod magazine "when looking for a suitable replacement engine for your Chevy,if you come across one in a salvage yard with "Hench En Mexico" cast into the block--"back away as if it were a rattlesnake" !..

(This was in an article on doing a "build up" ,making a 350 with 6" rods and other modifications put out over 400 HP on pump gas)
I don't think they were THAT bad,not for a daily driver car or truck,but if you were going to bore one out,make it a high output race engine,etc,then I could see their point..many customers who bought the Mr.Goodwrench or Target Master engines had good luck with them..
 
diesel4me said:
I read once in a Hot Rod magazine "when looking for a suitable replacement engine for your Chevy,if you come across one in a salvage yard with "Hench En Mexico" cast into the block--"back away as if it were a rattlesnake" !..
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I ran a Hecho in Mexico crate motor in a 1982 3/4 ton long bed for 100,000 miles and it never skipped a beat. Ran it hard with 36" swampers for a decade. Daily driver and mountain camping. I personally wouldn't worry about them.
 
Me neither--I take what I read in those types of magazines with a skeptical attitude,they seem to diss certain things just because a few were lemons,or they happened to have sour luck with ONE ..(like the engine I mentioned that had loose rod bolts,no one is perfect)..|
--kind of like how the "all 307's are junk" reputation started, because many ate cam lobes, and or people put them in a heavy car or truck,then whined because they were not tire smokers in stock form..

They were never intended to be a high performance engine ,(not with the smaller 2GC two barrel carbs,low compression,"smog" heads )--they were just a "base" powerplant for most of GM's vehicles back in the 68-73 year range,intended to replace the old reliable 283's..
I had a few of those too,and they were good runners,dependable,and not to hard on fuel..
 
Unless you want something special I also vote for the crate option. I’ve have one 18 years with no problems. It’s getting tired now but still running decently powerful.
 
I went with a GM crate engine for my K5 as it is a tbi smog truck. It has been great. I have had a few engines built for my 79 C20. Hyper pistons are fine and I have them in a built 406 sbc. It has a roller cam, forged crank, aluminum heads with some work, 10.2:1 CR. It is built as much as I can get away with in a smog state. I have had problems with engine builders, even with great reputations.

A crate engine is great for stock replacement and an LS would be much better than building a high performance gen I, when possible.
 
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