marcar1993 said:
YO marcar? why are you telling him to run a late 350? 73-80? 77-80 are window main junk blocks.... and 73-76 while better have poor #8 heads.... i believe you mean for him to run a 1968-1972 350
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YO marcar? why are you telling him to run a late 350? 73-80? 77-80 are window main junk blocks.... and 73-76 while better have poor #8 heads.... i believe you mean for him to run a 1968-1972 350
If he can get an early 350, great, but if he can't a 77-80 has no major difference over a 403. Built in the same era. He's looking into a 20 hp boost out of a cam, with a little machine work even a late 350 will perform better than a little 307. If he can get some 5, 6, 7, or 7a heads for a late 350, the only difference is wmw, whih isn't too bad unless he's spinning the thing 5000+ rpm. For a street motor, ANY 350 is better than a 307, at least with the same money invested into it. And, definatly, if you can find a 72 or earlier 350, jump on it, those are your best perfomers.
I was wrong about the cam; my buddy Vern in CO says it went to the scrap with the block; we used a used diesel roller cam because we had a roller 307.
All he can remember is that we drilled out the bolt holes to 1/2" and ground on the pushrod holes. We ran Fel-Pro head gaskets for the 330, but maybe we ground on the coolant passages a little, I don't remember. We can only think of two mods. Head bolt holes and pushrod holes. Since we used the 330 intake and 4bbl carb, along with manifolds, I don't think we did anything else...
Typically, we ran the gaskets that matched the heads on whatever frankenstein we ran. If coolant passages were off (like on our Buick engines) we either ground them to match or plugged them with block epoxy (like belzona) to make it match. I wouldn't consider those head mods, though, they were block mods.
It's been a while since I've done that stuff (like mid-90's) so I'm scratching the back of my head. I know that it DID run, and run really well.
I just don't want people to constantly hear that this or that can't be done. It also doesn't cost a fortune in a machine shop to make things work well. Most machinists can't imagine things being done in a garage without some sort of Sunnen tool...
All he can remember is that we drilled out the bolt holes to 1/2" and ground on the pushrod holes. We ran Fel-Pro head gaskets for the 330, but maybe we ground on the coolant passages a little, I don't remember. We can only think of two mods. Head bolt holes and pushrod holes. Since we used the 330 intake and 4bbl carb, along with manifolds, I don't think we did anything else...
Typically, we ran the gaskets that matched the heads on whatever frankenstein we ran. If coolant passages were off (like on our Buick engines) we either ground them to match or plugged them with block epoxy (like belzona) to make it match. I wouldn't consider those head mods, though, they were block mods.
It's been a while since I've done that stuff (like mid-90's) so I'm scratching the back of my head. I know that it DID run, and run really well.
I just don't want people to constantly hear that this or that can't be done. It also doesn't cost a fortune in a machine shop to make things work well. Most machinists can't imagine things being done in a garage without some sort of Sunnen tool...
KrisW said:
i just find it odd that nobody ever brings this up when it comes to 307s... your right the pushrod holes and the heads need attention...i was going to say what did u do for the rockers? cause those heads had a shaft style system for that year...
i just found out that the stock 5A heads chamber was also a lil too large for the 307...i cant believe that would be efficient tho..
We ran the shaft rockers!
All of my Buicks had them and I think they're great. Lots of racers like to convert over to them as well on chevy motors, too. If I recall, the rockers were adjustable on those shaft setups. It was really uncommon, and I don't know why Olds didn't stay with them.
All of my Buicks had them and I think they're great. Lots of racers like to convert over to them as well on chevy motors, too. If I recall, the rockers were adjustable on those shaft setups. It was really uncommon, and I don't know why Olds didn't stay with them.
KrisW said:
thats pretty sweet.. i couldnt believe it..anywhere ive seen everyone was like the only head for performance use is the 5A...i wanted to bolt on my 3s but everyone was like NO its not going to work. i contacted several engine guys and they all said the same thing...NO dont do it... it will run but very poorly! im glad it worked out for you
I don't know if it matters, but I think mine were number 1, not 3. I'm pretty sure the 3 heads use normal Olds pedestal rockers.
I just think if you have the time, and very little money, sometimes the experiment pays off.
Olds engines are by far the toughest that GM has made. I am partial to Buicks but if I had to do it all over I would have started with Olds in the beginning.
Keep the faith!
I just think if you have the time, and very little money, sometimes the experiment pays off.
Olds engines are by far the toughest that GM has made. I am partial to Buicks but if I had to do it all over I would have started with Olds in the beginning.
Keep the faith!
indeed... how did that 307 run with those heads anyway..im sure you still had to run premium to keep em from pinging..
It didn't do too bad. I don't run premium gas in anything...
After the swap, we could beat any stock 305 chevy around, even TPI. We were running an old, old, old rochester 4GC carb and a late 70s big cap HEI with vacuum advance. If it did ping, I probably just took a little timing out of it. I know I always lose a little power setting the engine up for 87, but that's the way I do it.
Looking back now, and not knowing what 5A heads were, I probably would just have used the intake and exhaust. The roller engine heads were so horrible that I'm sure half the increase in power was ditching those with their matching manifolds!
I didn't have any block problems with the 307 like people say they have. I did use the 330 crank (I didn't know it was steel!!!) because the 307 piece was scratched up. I guess the 307 has a lightweight crank that grenades itself like the 301 Pontiacs did.
The last cam it got in the end was some custom grind that my buddy Vern got (Crower maybe? or Lunati?) with a lot of lift. The engine wasn't mine anymore and it grenaded shortly thereafter after scaring a lot of Camaros and Firebirds! I went diesel after I sold that engine and didn't run another gas Olds engine until a few years ago...
After the swap, we could beat any stock 305 chevy around, even TPI. We were running an old, old, old rochester 4GC carb and a late 70s big cap HEI with vacuum advance. If it did ping, I probably just took a little timing out of it. I know I always lose a little power setting the engine up for 87, but that's the way I do it.
Looking back now, and not knowing what 5A heads were, I probably would just have used the intake and exhaust. The roller engine heads were so horrible that I'm sure half the increase in power was ditching those with their matching manifolds!
I didn't have any block problems with the 307 like people say they have. I did use the 330 crank (I didn't know it was steel!!!) because the 307 piece was scratched up. I guess the 307 has a lightweight crank that grenades itself like the 301 Pontiacs did.
The last cam it got in the end was some custom grind that my buddy Vern got (Crower maybe? or Lunati?) with a lot of lift. The engine wasn't mine anymore and it grenaded shortly thereafter after scaring a lot of Camaros and Firebirds! I went diesel after I sold that engine and didn't run another gas Olds engine until a few years ago...
i cant find any cam listing for lunati and the only roller cams i saw for the 307 are the mondello racing ones for like 400$ not worth the $$$$ for me
so i guess there is no cheap way to make a little more power out of this then ?
so i guess there is no cheap way to make a little more power out of this then ?
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