[JLuger]

Originally Posted by Will

Well, if you'd really rather have the 350, then go for it.

There's a reason Pontiac put 455s in their biggest, heaviest cars rather than 350s. There's a reason why guys who want to go as fast as possible build bigger engines too. If none of that's important, any old engine will do. Heck, you could always put a turbo on that 350.

I know I know the reason I was leaning towards the 350 is that I had a better idea of what was done to the motor while the 455 seller didn't have much info and it didn't seem to be as well kept. But after getting input from the forum I'm going 455...

[67gtospud]

Originally Posted by JLuger

I know I know the reason I was leaning towards the 350 is that I had a better idea of what was done to the motor while the 455 seller didn't have much info and it didn't seem to be as well kept. But after getting input from the forum I'm going 455...

Regardless on which engine you buy I would (at the minimum) tear them down and replace all the gaskets while it’s out. This will allow you to have a good look at what you’re working with. Possibly replace the rod bolts for cheap insurance and also at this point would be a good time to change the cam if you wanted.

[Will]

Originally Posted by 67gtospud

Regardless on which engine you buy I would (at the minimum) tear them down and replace all the gaskets while it’s out. This will allow you to have a good look at what you’re working with. Possibly replace the rod bolts for cheap insurance and also at this point would be a good time to change the cam if you wanted.

You would replace the rod bolts without resizing the rods? That seems risky...

[steve25]

That can be done only if the Rods are then checked for being within spec which is 2.3745"/ 2.3750".

[1965gp]

If they run good and you aren’t going to test it’s limits then I would install it as is.

[JLuger]

Originally Posted by 1965gp

If they run good and you aren’t going to test it’s limits then I would install it as is.

That's my plan for now. I know if I start pulling it apart who knows where it will end.

[mgarblik]

Originally Posted by steve25

That can be done only if the Rods are then checked for being within spec which is 2.3745"/ 2.3750".

This is a very important point. It is a recipe for disaster to replace stock rod bolts with new stronger bolts, like ARP which have a higher torque value, (clamp load).
The housing bores WILL be distorted and bearing failure is more likely than just leaving it alone or as steve25 says, recondition the rods. If this is a tight budget job, might want to look at a couple bearings, and if OK, put it in and run it.

[67gtospud]

Originally Posted by Will

You would replace the rod bolts without resizing the rods? That seems risky...

I should've specified I would have the rods checked while apart, my mistake for leaving that out.

[65sport]

Question: Does the 66 have all the stock brackets, pulleys, and timing cover ? Do you plan on running AC ? Do you have an HD core support that will accommodate a 4 core radiator ? Does the 455 have a timing cover ? What model year is the 350 ? This is all relevant in regards to fitment, and cooling system efficiency especially if you run the 455.

[JLuger]

Originally Posted by 65sport

Question: Does the 66 have all the stock brackets, pulleys, and timing cover ? Do you plan on running AC ? Do you have an HD core support that will accommodate a 4 core radiator ? Does the 455 have a timing cover ? What model year is the 350 ? This is all relevant in regards to fitment, and cooling system efficiency especially if you run the 455.

No parts left on my 66 just the trans the 350 has been sold.
I had a heart issue so I'm on light duty for awhile maybe not a gd thing because its giving time to collect parts LOL

[455Grandville]

Originally Posted by hurryinhoosier62

Assuming any are left, Bart. 350Ps get scrapped at an alarming rate.

Yes, they are, but I prefer a 400-455. Even though my T/As 1971 455 is Unrebuilt-stock it pulls away nice.

[389]

455 + 068 = FUN!!!

[track73]

Way back a while ago I called and asked about installing new ARP rod bolts on my stock Pontiac rods. He replied that there was no need. In fact he said "did you ever hear of Pontiac rod bolts breaking?"But that had to have been 30 years ago. H.O. also said if you can read the print from the bearing on the big end it's probably okay. And line boring was't really needed on these Pontiac engines. But that was probably from the 90's too.

[77 TRASHCAN]

Originally Posted by mgarblik

This is a very important point. It is a recipe for disaster to replace stock rod bolts with new stronger bolts, like ARP which have a higher torque value, (clamp load).
The housing bores WILL be distorted and bearing failure is more likely than just leaving it alone or as steve25 says, recondition the rods. If this is a tight budget job, might want to look at a couple bearings, and if OK, put it in and run it.

The thinking in the good old days, may still apply today... pull the rod cap furthest from the pump to hopefully make sure it had been getting oil.

[rwarnerjr]

This is a real Question?

[JLuger]

Originally Posted by rwarnerjr

This is a real Question?

It was LOL!!

[goatwgn]

I have driven a car that had a 400 in it, and then had a 455 installed, pretty much stock for stock, and you could feel the extra torque those 55 extra cubes bring along. My own car felt completely different going from a 326 to a 455. You will not be sorry you went with the 455. And if you ever hop it up in the future, you can get more power out of a 455 a lot easier than the 350 (354).

[beertracker]

Originally Posted by JLuger

Looking for opinions . I have a 66 project Goat that nds a motor, came across 2 and can't decide what one to go with this is a back burner kinda driver project, both are Pontiac's one is a 68 350 bored 30 cam a little head work with a edelbrock intake probably 10k on it. Other is a 73 455 with a stock rebuild 15-20k on it. The 350 comes with all the accessory pulleys, alt etc. that I nd 455 is just motor.
Both run good $1200 apiece. My car is a m22 with 3.55's I'm leaning towards the 350 thoughts?

If it was me I would go for the 455. With either engine you choose take it apart and check the internals.

I would check each main and rod cap for wear and proper oiling. Are the journals smooth and free of scoring? Same for cylinders. If you are going to re-use the rods I would have them checked at the shop. You may want to measure the parts to see if they are within spec if you have the tools or you could take the short block to a machine shop for cleaning and inspection. If you are considering zero decking the block now is the time.

I would plan on replacing the oil pump, water pump, timing set, fuel pump, oil seals, gaskets and bearings since you don't know the history of the engine

Good luck and I hope you enjoy your 455!!
bt

[JLuger]

Originally Posted by beertracker

If it was me I would go for the 455. With either engine you choose take it apart and check the internals.

I would check each main and rod cap for wear and proper oiling. Are the journals smooth and free of scoring? Same for cylinders. If you are going to re-use the rods I would have them checked at the shop. You may want to measure the parts to see if they are within spec if you have the tools or you could take the short block to a machine shop for cleaning and inspection. If you are considering zero decking the block now is the time.

I would plan on replacing the oil pump, water pump, timing set, fuel pump, oil seals, gaskets and bearings since you don't know the history of the engine

Good luck and I hope you enjoy your 455!!
bt

Thanks BT

[HWYSTR455]

Buying a used engine is pretty much just buying someone else's problems, after a couple of those, you will end up building a fresh one anyway, so just cut to the chase.

Those 'in between' engines you will pump money into as well, furthering the cost-gap to your end solution.

What's the original engine that you are replacing? Do you still have it? Is the block and heads good? Maybe look into getting that rebuilt. A 'general' rebuild shouldn't be too much, but it will be more than 1200.

It's true it costs the same to rebuild a 350 as it is to rebuild a 455, so, if you're rebuilding, go for displacement.

If you're trying to chose between 2 running engines, displacement is still the factor. Chose more.

You can also reach out to builders such as Spotts Performance, Butler, KRE, DCI, etc and see what kind of a quote you can get on a basic rebuilt engine, most are in the $4500 range for a 455 short block.



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