Help I.d camshaft

[Ypsik10]

Sorry having trouble sending pictures again

 

[MikeB]

I would say 325 (give or take) horsepower. The headers help, but the big gains are always gonna come from how well your heads flow combined with how effective your cam is in conjunction with your heads. With the aforementioned head work, plus your cam intake, headers, I would venture a guess of 400 horsepower. This is just me saying this, though. I'd like someone else to chime in.

Well, the hottest 350 used in the 1970 Corvette was rated at 370 hp @ 6000 RPM with a fairly big solid lifter cam and 780 cfm Holley carb. And that was still "SAE gross" hp back then, which is essentially today's "dyno shop" horsepower.

Now maybe those numbers were artificially low for insurance reasons, but I still think an honest 400 hp would be hard to attain from a 350 with that Comp 268 cam, and even 9.5:1 compression. You'd have to build it to rev to >6000 RPM to make 400 hp. Or use modern heads, something like AFR 195s, but still use a bigger cam than the 268.

 

[Ypsik10]

Sorry still having trouble with pictures

https://annarbor.craigslist.org/pts/5966780613.html

 

[MikeB]

Looks like no threads are missing, so this may work in a low budget situation:
Run a bolt through a grade 8 flat washer to see if it will tighten at least 6 turns, and that the threads will hold 30-35 lb/ft torque. (Choose a bolt that will not bottom out.) If the casting doesn't bulge out, you're probably OK.

As for the used cam, if you don't know which lifters went on each lobe, then don't use it! Even so, I wouldn't use the cam and lifters if they came out of another block. Cams and lifters are cheap compared to tearing down an engine with a wiped cam lobe. I assume this not a roller cam, right?

Never did hear if the pistons are flat top or dished.

 

[1987 GMC Jimmy]

Well, the hottest 350 used in the 1970 Corvette was rated at 370 hp @ 6000 RPM with a fairly big solid lifter cam and 780 cfm Holley carb. And that was still "SAE gross" hp back then, which is essentially today's "dyno shop" horsepower.

Now maybe those number were artificially low for insurance reasons, but I still think an honest 400 hp would be hard to attain from a 350 with that Comp 268 cam, and even 9.5:1 compression. You'd have to build it to rev to >6000 RPM to make 400 hp. Or use modern heads, something like AFR 195s, but still use a bigger cam than the 268.

Makes a lot of sense. I understand that 400 is on the liberal side, and the cam may not be enough, but I think those 461 heads having been unshrouded to flow as much as possible and revalved could go somewhere.

 

[1987 GMC Jimmy]

Sorry still having trouble with pictures

https://annarbor.craigslist.org/pts/5966780613.html

Is he willing to accept $250 down from $375? That seems more flexible than you'd expect, but I've never sold a set of heads before. That chip is on the intake side, and it doesn't interfere with the mating surface so I would say it's okay, but if you want more power than what we're proposing here, you'll need more than the 461's. Plus, I'm curious on why he budged on the price as much as he did.

 

[Ypsik10]

Looks like no threads are missing, so this may work in a low budget situation:
Run a bolt through a grade 8 flat washer to see if it will tighten at least 6 turns, and that the threads will hold 30-35 lb/ft torque. (Choose a bolt that will not bottom out.) If the casting doesn't bulge out, you're probably OK.

As for the used cam, if you don't know which lifters went on each lobe, then don't use it! Even so, I wouldn't use the cam and lifters if they came out of another block. Cams and lifters are cheap compared to tearing down an engine with a wiped cam lobe. I assume this not a roller cam, right?

Never did hear if the pistons are flat top or dished.[/QUOTE

Pistons are not flat top stock Pistons from a 74 350 2 bolt slightly dished with 4 valve reliefs machine shop said 64cc will not put my compression to high .. I'm weary and not sure if I would buy them .. Would that make them more likely to get a crack?? Can't find any other 461s .. Other than my machine shop down the road 600$ guide plates 3 angle valve job ungraded springs... I have a MASSIVELY junkyard neer me with tons of Chevy trucks I think they only charge 35$ a head for cast heads was thinking about maybe spending a whe day pulling some vortecs???

 

[Ypsik10]

Looks like no threads are missing, so this may work in a low budget situation:
Run a bolt through a grade 8 flat washer to see if it will tighten at least 6 turns, and that the threads will hold 30-35 lb/ft torque. (Choose a bolt that will not bottom out.) If the casting doesn't bulge out, you're probably OK.

As for the used cam, if you don't know which lifters went on each lobe, then don't use it! Even so, I wouldn't use the cam and lifters if they came out of another block. Cams and lifters are cheap compared to tearing down an engine with a wiped cam lobe. I assume this not a roller cam, right?

Never did hear if the pistons are flat top or dished.

As for lifters I don't have any they would be ordered brand new..

 

[MikeB]

Pistons are not flat top stock Pistons from a 74 350 2 bolt slightly dished with 4 valve reliefs machine shop said 64cc will not put my compression to high .

...was thinking about maybe spending a day pulling some vortecs???

Yes, compression should be OK with those pistons.

Unfortunately, there's a good chance used Vortecs will have some minor cracks. I think 2002 was the last year for them, so anything you get will be at least 15 years old.

Here's an article on small block heads, with an emphasis on Vortecs.

https://www.onedirt.com/tech-stories/engine/a-guide-to-vortec-vs-oe-small-block-chevy-heads/