Help with heads...Please!!!

[Corey13]

Hey guys, im a new member but ive been lurking a ehile and used yalls information alot. Im hoping yall can help me. A little back story, I have a 92 sierra 1500 that ive had for like 10 years and it has tite at 400000 miles on it. My daughter has said that she would like me to pass it to her. Its getting a little tires, so im building a motor for it and am just gonna do the swap once the motor is built. I bought a 350 on the cheap knowing i was gonna rebuild it. Im taking it to the machine shop to get it cleaned and bored 30 over on monday. The machine shop has a swap option for heads, but they have to be buildable... The ones that ate on this motor are not considered that, too much rust and pitting. My question is, i checked the casting numbers and they are 1402193 heads, and my current motor (305) also has 1402193 heads. The only info i can find is that those heads were used on both 350/305, so im wondering if they are the same. I ask because those are relatively fresh heads (i did the exchange about 5000 miles ago) and if i can just use those, that will save me some money to put towards other stuff for the conversion to 350 and to make the truck a little nicer for her. Any help or input would be appreciated. Thanks

 

[kennythewelder]

Heads from a 305, will work on a 350. What you don't want to do, is put heads from a 350, on a 305. The size of the chamber on 305 heads are a little smaller on the head to fit the cylinder of a 305.

 

[Erik the Awful]

Most people consider the 193 heads to be garbage, but supposedly they're good for fuel mileage. You can get a little more flow out of them with a couple hours worth of porting work. I built a 350 .030" over with 193s and have it sitting on my run stand, ready to test fire. Did your machine shop say the old heads were too pitted? My motor had rust crystals in the lifter valley and the #1 combustion chamber was full of water. The machine shop I used had no problem cleaning it up.

The rule in my house was "No V8s for teenagers." If you are going to build it, I'd stick with the stock dog-slow camshaft, at least until your daughters get a few years of driving under their belts.

 

[Corey13]

My maxhine shop said they werent buildable for the exchange. I guess that it would be more man hours to clean them up than the 250 to exchange them

 

[Corey13]

I had plans yo go all out until she said that, so yeah its going to be a very mild build

 

[98 Nitro]

305s should have 187 casting # I believe

 

[PlayingWithTBI]

Or you could go with these, they flow better than Vortec heads and everything on TBI bolts right up.
www.summitracing.com/parts/sum-162108

 

[BOOT]

See if there are any crate engine take offs with no or low miles in your area, use to see them from time to time around here. People get a cheap gm crate and then swap to better heads. Otherwise compare new heads vs the total cost of labor and parts of getting yours redone, sometimes it about the same But you gamble on the local shop's work quality.

 

[Erik the Awful]

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At $353 each, you can't beat the price, but you'll want some flat-tops to make up for the 72cc chambers.

 

[Schurkey]

but you'll want some flat-tops to make up for the 72cc chambers.

"Flat-tops" make up good compression on ~65 cc chambers.

They're not enough to crutch a bigass 72 cc chamber. And that's twice as true considering how many "flat top" pistons don't have proper compression distance.