trying to decide what to do with my 1970 340. I'm getting ready to pull the engine and trans from my prostreet duster. I can't seem to decide wether to rebuild it into a 416-420 or just buy a crate engine. I'd like it to make 500hp normally aspirated and possibly install a troque storm supercharger. If I rebuild the 340 I can get a compression ratio thats more suited to the supercharger. Crate engines seem to be around 10:1. Also seems like most crate engines I've looked at use cast cranks. Seems like forged would be better but maybe its just over kill. Opinions?
Stroke old 340 or new crate engine
- Thread starter WCMachine
- Start date
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This...You don't need a supercharger to make 500 horsepower... Here is a better question(s): What is your plans for drivability, pump gas (?), and is really 500 horsepower, a goal?
I have a buddy that built a 416 out of a 340. Torque monster and right around 500hp on pump gas.
MOPAROFFICIAL
Oogliboogli
If the 340 runs, set it aside.
Get a 360 block, probably cost you 100-200 bucks, then just buy a rotating assembly from scat or Ohio crankshaft. If you want to make a real streetable 500 hp...you'll wanna get heads that are strong in the low- mid lift.
As well as peak. Say they peak at [email protected] better flow around 250 by .400
That's how i see it.
Get a 360 block, probably cost you 100-200 bucks, then just buy a rotating assembly from scat or Ohio crankshaft. If you want to make a real streetable 500 hp...you'll wanna get heads that are strong in the low- mid lift.
As well as peak. Say they peak at [email protected] better flow around 250 by .400
That's how i see it.
stroked340
Well-Known Member
Do the 340..don't trust any crate(crap) motors...
It's a prostreet duster with 21.5x33 mt's. It has manual brakes and steering no heat or wipers. Im not overly concerned about daily drivability as we mainly cruise it to shows. This may sound lame but it needs to look and sound the part. It sounds the part now but performance is poor.
Start with dumping the Performer intake and stoke it yourself. It will be set up for you rather than how the companies do it.
Absolutely, if it's not numbers matching.. And if you want to spend 3k more,to make it RIGHT. I worried / worked, in a speed shop ,for three years. Amazing the stuff that survives ,prepped correct.
Yes, the end bolts on each side of each head have Coolent behind them. This is normal.
MOPAROFFICIAL
Oogliboogli
Yes, the end holes go into coolant.
Good to know, thanks
I dare you to describe " poor" .. That car with 400 honest horsepower, should run 11's .. I call it ,good.
What a beautiful Duster....
Yea, BUT, it would look awesome with a tunnel ram sticking out of the hood!!!
MiradaMegaCab
Well-Known Member
As being that it's not my money, build a blown and stroked 340! Custom pistons with around-40CC's will keep the CR boost friendly.
Unless you go with a blown and stroked 360. Icon has a off the shelf piston (IC982) for the 408CI with a -34CC dish that will result in a boost friendly 8.6CR with 63CC heads.
You might be able to run a crate stroker with "high" CR and boost on E85.
Unless you go with a blown and stroked 360. Icon has a off the shelf piston (IC982) for the 408CI with a -34CC dish that will result in a boost friendly 8.6CR with 63CC heads.
You might be able to run a crate stroker with "high" CR and boost on E85.
NorthernNYMOPAR
Active Member
I personally take great pride in building my own stuff, sure you can buy a crate motor, but anyone can, the personal pride of knowing "built not bought" is something you can't buy....sure risk you make mistakes but if you care and take your time it is truly yours
You and I both buddy! I do everything
except the machining of the block, heads and crank. It’s fun.
Well maybe I was a little harsh. It did run real nice with great throttle response just not awesome performance. My last project was a CTS-v wagon 6 speed manual with 565hp at the tires. Maybe that's my problem
WSUTARD
Well-Known Member
Funny. I’m going through the same question in my head. Except my 340 is in a Coronet and I’m debating between stroking my 340 or building a 440. I have already purchased a 440 block but haven’t made up my mind yet.
Then I suggest a 4spd auto at a min. if you can!
I suggest the big block for the B body.
You can find excellent information from member Andy F.
pink340swinger
Well-Known Member
If it is not numbers matching to the car, why don't you post pics of the vin number and casting numbers on here? Someone may be looking for their long lost 340 to put back in their car!
The chassis is a 1974 and the VIN indicates it was originally 318 powered. I'll post the block numbers in the lost and found but it would need to be an exact match with proof for me to let it go.
furrystump
Well-Known Member
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With a 408 and a good flowing head your in the 11's. Like stated before post the vin, if no response either build the 340 or store it and build a 360. Stroke either one.
WSUTARD
Well-Known Member
You and my wife have something in common, you both know how to spend my money really well!
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