Which block to start my build?

[mbaird]

If it is just a street cruiser it will have maybe 10.5:1 compression and a mild cam ( 240 @ .050 max duration) so I would use the .060 block OR find an early 360 (5.9) magnum roller block and go hydraulic roller cam to avoid potential lobe loss on break in . Plus you can use the magnum lifters and save $ .

 

[furrystump]

I would keep the 340’s and find an unmolested 360. Start with that. The 340’s have enough value to me and 360’s are not that hard or expensive to obtain. Doesn’t really matter which you start with as to performance. I’m running a 360 based stroker and my spare block is also 360 based. Chance of hurting something with me is prettty real.

 

[ValiantRacing]

I would run the .60 over block, if you use a good head it will appreciate the 4.10 bore

 

[CRUZE 418]

If I ever build another, it will be a 318 stroker. I have 2 blocks that didn't cost anything. They will run just as good as a 408, at 390 or so cu in.

 

[67_Slimer]

If I ever build another, it will be a 318 stroker. I have 2 blocks that didn't cost anything. They will run just as good as a 408, at 390 or so cu in.

Well the reason I have these blocks is because my original plan was to try and build a nasty 340 and now I’m leaning towards building a stroker. Still up in the air on that lol.

 

[CRUZE 418]

You can always BS'm with your 318, it looks no different. It's up to you, 340's are just worth so much compared to dime a dozen 318's. I have a standard bore 340 bare block, but I would still do a 318 if I blow or window the 418.
Go get'm!

 

[TT5.9mag]

If I ever build another, it will be a 318 stroker. I have 2 blocks that didn't cost anything. They will run just as good as a 408, at 390 or so cu in.

Peak hp will vary quite a bit with the same heads/cam on both engines because of the 18 cu/in difference. Just like 340 vs 360. Or 340 vs 318.

 

[TT5.9mag]

Use whichever block sonic checks the best. Don’t guess.

 

[CRUZE 418]

I'm just saying for the street, 20 cu in isn't a big deal. I've seen 383 SB Chevys run pretty damn good!

 

[Ant]

I have not checked 340 prices in a little bit, but from the chat here it seems like 340 blocks might be worth more than they did a couple of years ago. Is it true? I don't know, but when I was looking for a motor a few years ago, people on the market places wanted big dollars for the most crappy 340 engines. Even the 360's were in the crackhead prices depending on the area, however there were a few good ones here and there.

I'm not an expert engine builder, but I do know the cost of things can pile up, especially what is unknown. So, in my opinion, build what you already have, if that block that's bored .060 over is fine, then why not have fun with it? Another new used engine could just be more new unknown problems.

 

[LO23M8B]

I just love the rpm's of a little 340. If you're thinking of going either way and you're not looking for the max h.p. the 340 built right should do the trick but cubic inches will run faster. You just have to match the parts correctly. I'd use the 060 over if the walls check out.

 

[BrianT]

Three years ago, I paid $1000 for a standard bore 1970 340 block. I had the seller take it to his local machine shop and I paid them $125 to mag and measure it. These good blocks are getting rarer and rarer every day. The prices will continue to go up.

 

[Mojoe9955]

Neither, use a 360 and save the 340s

Save them for what?

 

[BrianT]

Save them for what?

I agree. In another 20 years, the people who know what a 340 is let alone want one will be a very small number. I say build them now!

 

[1WildRT]

And I say use a 89-93 360 because you get an easy way to go roller cam...

 

[MOPAROFFICIAL]

And I say use a 89-93 360 because you get an easy way to go roller cam...

View attachment 1716536607

Thats what I have for my next one. 88 cast block for 89 year, roller

 

[67_Slimer]

I agree. In another 20 years, the people who know what a 340 is let alone want one will be a very small number. I say build them now!

View attachment 1716536597

Couldn’t agree more. Save them for what? For someone else to enjoy? I’ll enjoy them now. Beautiful looking motor BTW

 

[LO23M8B]

20 years. You are very optimistic. They way things are going I don't think this country will be here. Even Rome fell.

 

[SixPaksRule]

Well...be sure not to over cam the stroker as many do...and put a thermoquad or six pak on top of it

 

[67_Slimer]

Well...be sure not to over cam the stroker as many do...and put a thermoquad or six pak on top of it

Solid flat tappet and a Holley 750 HP

 

[furrystump]

Would this be over cammed?

 

[LO23M8B]

Dumb question. Manual or auto? Converter, gear ratio?

 

[Dart Frog]

If you can handle large gear ratio rear end a hot 340 is no slouch even in today's terms. Mine will run right with my SRT 392 in the 8th mile. But a stroker will be More Street friendly and allow you to run a much friendlier rear end ratio and not give up anything except maybe rear tire life. I don't think there's really any reason to save anything unless you have someone who just wants to pay you top dollar. Build what you want!

 

[67_Slimer]

Dumb question. Manual or auto? Converter, gear ratio?

Manual, 4 speed with 4.56s

 

[67_Slimer]

If you can handle large gear ratio rear end a hot 340 is no slouch even in today's terms. Mine will run right with my SRT 392 in the 8th mile. But a stroker will be More Street friendly and allow you to run a much friendlier rear end ratio and not give up anything except maybe rear tire life. I don't think there's really any reason to save anything unless you have someone who just wants to pay you top dollar. Build what you want!

Well I have 4.56 gears and I don’t want to change it lol.