[77 TRASHCAN]

Originally Posted by kyle_blake

Not sure if you are interested but the engine i just took apart 428 ,had a way to small cam in it. I kept all lifters in order and the cam looks in excellent condition. I'm up in Canada though and I'm sure you have more options closer to you. exchange cam as someone suggested.

let me know if interested. i attached the spec of cam , it was made by CRANE.

I tried to send you a PM, but your mail box is full....

[77 TRASHCAN]

I've read this thread over, several times...
This VERY low compression 350 with a smallish cam, I'm questioning why it ran as it did with its seemingly too small cam???

This post is not to knock the OP'er, I'm just thinking out loud....wondering....

There's not a lot of conversations here about pepping up a low compression engine, some, but not that much.

My 77 TA had a similar cam in it's 400 (7.6:1). It ran quite well, for what it was. The governor in the transmission was set to shift at 4000 RPM's, that was a perfect RPM for that engine...The factory engineers did a great job of making that low compression 400 perform. The factory spec was 18 degrees initial timing. I always made sure mine was right on that spec. On a few tanks of gas, it did ping. I knew what that was telling me, and drove more careful, to avoid that...

I would think that the 537441 cam would be about the best choice for that engine??? maybe not???

I pulled my 400 in 1992, the #7 exh. lobe gave up...I performed a low dollar rebuild on a 1970 350 (new rings, bearings, cam lifters, factory iron 4 Bbl intake, Quadrajet). The cam I used was a 066 replacement. It performs fairy well. I've had as much as 44 degrees total timing in it, couldn't make it ping. I've often wondered IF that 066 cam was a tad too much for my weenie 350...I think the compression ration with the stock #11 heads, is just TOO dad gum low. It's advertised as 8.8:1, I know its NO WHERE near that. I'm sure its under 8:1
I' didn't cc those 11 heads. I did do a lot of mild grinding to help them...

From my experiences a low compression 400 is still a decent performing engine, a low compression 350, not so much

Anybody else got thoughts???

[moontower69]

I hear you 77Trashcan on why performance so weak. I'm not a newbie and tuned this car to perfection over the years (put 100k on it over 13 years as daily diver) and since day 1 it noses over at 2400prm, like turning a switch off - will rev to 5000 if hold it in first and chirps tires but that's it.

I pulled the heads and measured the bores, they look great, maybe 1 to 3 thousands wear/taper. Its .030 over, stock pistons/assembly/rods and I'm gonna measure the spring pressures, my theory is the PO rebuild put in wrong or weak springs and its why this thing was so weak.

Either way, picking up #17 heads on Wed in Barstow CA - will confirm new spring pressures and cc the heads (guessing about 81-83 cc). Will be happy with a 8.9 or 9.0 compression and 067.

Re-using the old pushrods - is that a bad idea? Have new Johnson lifters though soaking in oil.

[steve25]

Please note that a stock intake manifold that sealed up at the exh crossover with the 4X heads will need a block off plate with the early 17 heads.

You should keep the push rods and rockers together as a pair if the push rod ends look ok to reuse.
I would assume that the push rods and rockers from your 4X heads have less miles then the 17s you are picking up, in fact look over the push rod guide plates and run the best 4 out of the 8 you will have.

[77 TRASHCAN]

Originally Posted by moontower69

I hear you 77Trashcan on why performance so weak. I'm not a newbie and tuned this car to perfection over the years (put 100k on it over 13 years as daily diver) and since day 1 it noses over at 2400prm, like turning a switch off - will rev to 5000 if hold it in first and chirps tires but that's it.

I pulled the heads and measured the bores, they look great, maybe 1 to 3 thousands wear/taper. Its .030 over, stock pistons/assembly/rods and I'm gonna measure the spring pressures, my theory is the PO rebuild put in wrong or weak springs and its why this thing was so weak.

Either way, picking up #17 heads on Wed in Barstow CA - will confirm new spring pressures and cc the heads (guessing about 81-83 cc). Will be happy with a 8.9 or 9.0 compression and 067.

Re-using the old pushrods - is that a bad idea? Have new Johnson lifters though soaking in oil.

You can check the old push rods by spinning them in a cordless drill. I'd just buy ne ones, they used to be cheap, but no telling, these days, Everything is over priced. Shop around. If the push rods spin alright, look carefully at the ends of them. Sometimes the holes split or erode some...

Getting the 17 heads milled
030 will help you..but cc them first.

I used Sealed Power moly rings in my 350. I like them. It's never used oil. I also used the positive fit valve stem seals on my 350.

Carry on!!!

[moontower69]

Ok, picked up heads and they are #47 and not #17. Do I still need an exhaust crossover BLOCKOFF plate with the #47 since I was running 4X heads before?

will post pics.

Heads just need springs, all valves new etc (1.96 intake/1.66 exhaust Ferrera I think).

What the best stock valve springs to get for this combo?

[moontower69]

Do these look good? Havent cc'd yet.