I have recently acquired a 1969 small block 340 with x heads. The motor is completely apart and stock bore. I am looking to get a reliable 350 to 400 hp. My question is who does a guy have do the machine work on the motor? I know that there are multiple engine builders in the area, I just want a guy that is good and knows mopar motors. I am willing to travel within a couple of hours from Eau Claire. Lets here what the HAMB has to say. Tony
For what it's worth there were a few dyno tests of brand new 340's that put out 325 hp absolutely stock, even tho they cheated for insurance company reasons and called them 275 hp. Hard to beat a stock 340 for a daily driver with a ton of power. One little bit of help is a 1968 stick shift only camshaft. They have a little more umph than the automatic cams in 68 and then the same cam in all 340's from there on out. If ya want that rumpty rumpty sound, go with just a little more cam than the 68 stick cam. Everything else is good to go. Don't know where to send you for a builder as I live across the country from you but don't let them talk you into building it like a SBC. The 340 pulls like crazy up to 6000 and without major oiling mods should not be run past that. They have a ton of torque. Dave
I don't know why they only lasted 4 years because like dwollom said they were monsters. you do know what you have with 69 block and xheads so don't let anyone talk you out of it Tom
call Don's in kenosha. Talk to the owner Tony. Tell him I sent you. They can get it done. Their work on something like that is outstanding. Tony runs a dragster and understands the racers needs.
Look around on the site Speed Talk. Lotsa engine builders/racers on there. Bound to be somebody near you! 6s
Thanks for the input guys. I mainly need to have someone to do the machining. I don't want to go overboard on this one. I have talked to a few shops around the area, and I just don't get the warm fuzzy feeling, when I talk to them. I don't know if there are any tricks specific to the 340 when machining, but the people I asked at the shops, said nothing special, just build it like a 350 chevy. I plan on stock crank, and bore only to clean up. I have 5 different intakes to choose from. I am in Pascagoula MS until mid Feb. so I can only talk to people until then. When I get back is when I will drop block off somewhere. I just want to know what they need to do the machining, rods, pistons, crank, cam. Brian, I will call Dons, and see what they have to say. I assume that you have used them before and had good luck with them. Also if there is any car things going on down here let me know, I have some time to see things. Thanks Tony
Hi don't know if this will help . I have a 68 block and had it rebuilt 30 over(it had a spun rod) and I had the pistons. A small 420 lift cam and a set of Magnum heads with jeep pushrods( so it would oil the top end). Stock oil pump and an after market intake with a 600 Holley. It dynoed at 330 hp and 392 ft lbs of torque. I put it a 1952 plymouth with a a500 overdrive from a 95 dakota with an ford explorer diff. It runs fine on pump gas. Nothing special but I can pass traffic on the highway with no problems ...... good luck with your rebuild.
Can't help with shop recommendations, but do check the crankshaft main bores for straightness. I had one that the rear saddle was out of square, and needed align hone.
I can't say from personal experience but I've heard good things about Goodwin Competition. On a quiet night I can hear their dyno from my house.
X heads, stock forged crank, stock windage tray, stock double roller timing chain, new stock oil pump, baffle the oil pan, stock intake manifold is terrific but if you can find an old Edelbrock LD 340 intake they are near perfect, very much like the stock intake but lots lighter. Early 340 HP exhaust manifolds if you can use them work great. Factory dual point distributor, etc, etc. The 68-71 high compression, 10.5-1 engines already had all the hot goodies. In 72-73 they lowered the compression to 8.5-1 (if that) and went to a cast, external balanced crank. Still rated them 275 hp which was closer to correct for those. Can ya tell I like 340's? I have 6 of them. Oh, and I repeat, do NOT let them build it like a 350! Dave
Try Herman's motor clinic in Baraboo, WI. I have him do all of our balancing and whatever machine work I cant get done here in town. 608-356-4732
All substantial race car shops and near Eau Claire Tim for sure can dyno it and perhaps the others as well. Haven't called on them since I retired a bunch of years ago. Baxter Engines, Inc. Eau Claire Tim's Auto and Machine, Bloomer Adams Auto, Cameron
I've always had good luck with Total Engine Service in Bloomington, MN: https://www.facebook.com/pages/cate...op/Total-Engine-Service-Inc-1539949036311689/ They're about 90 minutes from Eau Claire.
I don't have any recommendations for specific shops, but have some experience with machine shops. And Mopar motors. My dad and uncle both worked in a machine shop for years and were very meticulous. They did all kinds of oddball stuff. Hit and miss engines, built stroker cranks for john Deere tractors, caterpillar engines, in addition to any kind of car engine out there. There really isn't anything particularly tricky about a 340. The key is to find a shop that does good quality work. I've seen plenty off sloppy machine work too...and it is always very disappointing. But for the most part a guy who does good quality work on a 350 will do good quality work on a 340, and a guy who does sloppy work on a 350, will do sloppy work on everything. The only thing I've encountered that sometimes throws off people is you will occassionly get a small block Mopar where the cam bearings are tight and you have to scrape them a bit. This pretty much never happens on a Chevy, so if you happen to have one of those blocks and the shop has never dealt with it they might not know what to do. If you are having them install your cam bearings. There are some decent books out there on rebuilding Mopar small blocks, but if you've done a few overhauls they won't be very enlightening. As for performance, the Mopar performance engine book will pretty much tell you what needs to be done to make whatever power you want to make.
It's super easy to get 400 hp from a 340, especially when X heads are part of the equation. I can't help you with a competent builder in your region, but these motors are fairly easy to build and any reputable shop should be able to get this motor machined and back together for you. Hot Rod did a feature on the 340 years ago. They installed a Comp solid cam and a 750 demon carb and pulled 458 horsepower on their dyno run.
These are some good spots to look at. I did look at dons, and Goodwin, wow didn't know they were in Wisconsin. I have had bad dealings with Baxter engines. Dropped a motor off in January, and they said no problem, kept giving me the runaround, went back later motor not done, said they didn't have time because of circle track season. Tried buying other parts from them, never again. I will keep looking and asking questions, it will happen. I read the hotrod article build up on a stock motor, and just added bolt on parts, they ended up with what I am looking for. Tony
I second on Don's in Kenosha ,have had a handful done there and NEVER a problem. I have a new cam, used intake and J heads going to be for sale. Msg me on facebook for info
Bugsy48, that's 3 votes for Dons so far. Depending on cam I might be interested but I am not on facebook.
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