Pulled My Motor - dissapointment

[think_07]

So this past week I got my motor pulled out of my blazer. I checked the rpo list, and originally the truck came with a "hi-po" 305, but this was replaced, with what the previous owner thought was a 350 after the 305 kicked the bucket, well I checked the casting numbers today and found that it was actually replaced with another 305 out of a '75-'79 car.. I thought this couldnt be right, so I checked the casting number on the heads, same story, so then i pulled the heads off and measured the bore.. yupp definetly a 305 haha. So I was pretty dissapointed, but got over it quickly, and am looking around my area for a 350 shortblock, maybe a reman if the price is right, hopefully someone with take my 305 as a core. I figured out the problem why it wasnt running well either, a chunk of one of the piston was broken off the top all the way down to the 1st ring, and part of the ring was also missing. The peices of piston and ring were no where to be found though, and they weren't embedded into the combustion chamber like I thought they would be, the combustion chamber was actually in great shape. So who knows. My plan for the build now will be a 350 bottom end, with 305 heads (not mine as they are not a good casting number) a performance cam, intake to compliment the bottom end power of the heads, a set of headers, and a truck avenger carb, 670 cfm. I've read all the different oppinions on running 305 heads, they don't make any top end power, but from what I have researched they should give me more bottom end grunt, and for a wheeling truck this should be great on a budget. The hunt for another motor begins this week, at least I have the right flexplate motor mounts, accessory brackets for my rig. Trying to see the positive here haha

 

[Hogback Fabrication]

I wouldn't run the 305 heads on your 350 (yes, I did read that you are looking for low end power).

 

[Disciples Performance]

that sux dude def well i have a shortblock you might be interested in lemme know your e-mail and ill let you know the specs im in BC

 

[4X4HIGH]

Unless you run the special pistons for using 305 heads on a 350 you will end up with a compression ratio so high you won't be able to run pump gas without it pinging and doing the same damage as you already have found. 305 heads are junk and don't flow good at all.

 

[think_07]

Alright well what do you guys suggest for a set of budget heads, I was looking at a set of trick flow 23 degree street aluminum heads, but I think they might be a little too pricey, any suggestions? I've read many times that a set of vortech heads would be good, does any one know how much a set of these would be new? I'm now sure that I would want them or not, I don't think you can run a very high lift cam in them. How about other aftermarket heads, aluminum or iron?

My e-mail is [email protected]

 

[Disciples Performance]

e-mail coming your way

 

[Disciples Performance]

i was gonna run edelbrock alum performer RPM heads they run for like 1200$ a set 70cc angled plug very decent head flow well and create lots of power!

 

[pauly383]

Thats a shame . Too bad you weren't closer , I'd give you a buildable core since I have so many now .

I have a 350 short block still in a 3/4 ton 78 Suburban . Ran before the heads were removed . Got a little rain in there , but would clean up nicely with a motor kit and a ball hone . 3970010 numbered block .

 

[vortec]

Unless you run the special pistons for using 305 heads on a 350 you will end up with a compression ratio so high you won't be able to run pump gas without it pinging and doing the same damage as you already have found. 305 heads are junk and don't flow good at all.

my old engine was a 350 with 305HO camaro heads, with everything else factory stock for the truck. the low-end torque was good, but the top-end was craptastic. i ran on 87 octane with no problems, but, i was probably losing compression from worn out rings and valvetrain, so i got away with it.

 

[Cowboy_80]

Hit up a junk yard and get a motor. Bring a compression tester with you and find something good. No less than 125 lbs per cyl.

 

[think_07]

Thanks for all the replies guys, I think I will be heading to the wreckers soon and see what i can find. If anyone in Alberta has a 350 shortblock or longblock they would be looking to pretty much get rid of let me know. What would be original compression per cylinder approximately, for a stock 350?
Thanks alot

 

[Cowboy_80]

I'm not sure what normal would be. Assuming it's a 8.5 compression motor, maybe 130ish. Don't know though. I got over 300K out of a used 327 that I passed with the 125 rule. had some at 125, others at 140. She still ran strong.