Only the early 348 truck blocks are "bad" blocks due to the double notches in the combustion chamber. The single notch 409 blocks are excellent bases for a stroked hot rod engine. Ross, Diamond, Keith Black, and JE all cut pistons for the 348/409 engines that can account for the decrease in compression caused by the notch. GOF***T's note on getting pistons with pin heights for a BBC 6.135" rod is a good one. Only the 409 p***enger car blocks were without the notches. 409 truck, 348 p***enger car, and most 348 truck blocks only had one notch. Some 348 truck blocks have two. The 'X' isn't limited to 409 blocks.
Using the BBC rod is not a bad idea. But if you're gonna replace the pistons and rods, might as well look at a complete rotating ***embly and go for the big cubic inches with a 4" stroker crank. Once you start, there's no stopping. Larry T
A friend of mine got his 409 from a mid-60s dump truck. Standard bore bore block but had water damage in two holes so got bored to .030 over. Added an Offy 348/409 2 4bbl intake and commenced to melting tires on his 64 Impala SS and his wallet for fuel expenses. Put a stock single 4bbl manifold on and still smoked tires but fuel cost wasn't that much better. Nothing prettier than a dressed up 348/409 except adressed up flathead Ford or Buick nailhead.
I like 'em, even better than a Flathead or Nailhead. This one started life as a truck engine: This one is a QB for a 62: And I'm picking up another QB from the machine shop today for a 63.
I would just add one more very important issue with respect to the pressed-in oil galley plugs. I would make certain whichever shop you choose to do your machine work they go and drill and tap ALL pressed-in ones. I believe there are about 10 or so? Another "positive" for changing the rods to the BB pieces is you now have the option of using the wrist-pin locks (available on most aftermarket pistons) as opposed to "pressing" the pistons and rods together! With the prices coming down on these rods it really doesn't pay to use the OEM pieces anymore! The "stroker" deal is a customer choice, many of my guys simply want the OEM stroke! With the 4.000" arm in there you can easily get 475"+ C.I. It will make a "ton" of Torque. Thanks, Gary in N.Y. P.S. If that build were top come in the door here (***uming a "custom" piston platform) I would go directly to the 6.385" BB rods. This will make the pistons somewhat lighter, even the aftermarket pistons are fairly heavy, the shorter C.H. will help with the balancing!
Larry--I read in a performance manual that a 409 crank will not rotate in a 348 block---yet I dropped a std 409 crank into my block today--casting 3751872 and there seems to be no clearance issues. I fitted an old rod and piston and around she goes. Is this issue limited to certain blocks or a "wives tale" My plan was to run this crank with .010 over pistons and and a mild cam. BB chev rods and Ross pistons----Am I way off here?
How will changing the the rod length lighten the pistons? Looks to me like you're just changing pin location unless the piston is a completely different forging. Larry T
Well I have learned a few things from this post. Got the complete 409 for $1,000, I think I did pretty well!! I did have him pull off the head and the relief areas were in it so it's a truck block. Big deal it's not like it's going into another Impala, if it were I would still be looking for a car 409. Instead it will be going in my 32 Ford Pickup. This pickup won't have much weight to it so I should be good with 400-425 hp. I want to keep things as stock and mechanical as I can. So I already plan on using 6x2 stormberg setup, mechanical fuel pump and a pusher electric fan behind grill for more room. Also will be going with a Winters quick change. So if I can try and use the rods in the motor I would like to with the replacement of the pistons to bring up compression and replace the normal stuff you normally would on a rebuild. Does anyone have any suggestions without replacing rods? What would be the parts I can reuse and what needs replacing? Also does anyone have any suggestions for a manual transmission??
John, Sounds like a plan to me. I really don't know about the clearance issues on a 409 crank in a 348 (380+ cubic inch I think) I think the big block rods might be a little beefier than the stock rods, so make sure you check your clearance with them. I have heard that a 348 pan won't work with a 409, so that would be something (minor) to watch for. As someone has mentioned, if you're serious about W blocks join the discussion group over on 348-409.com. Some of those guys have been messing with this stuff everyday since it was new. LOTS more knowledge than I have about the engines. Larry T
As GOSFAST mentioned, from a performance viewpoint the BBC rods make a lot more sense than stock rods. The 2 QB engines I've messed with still have the stock rods in them (because the owners wanted as close to stock engines as possible), but we had them rebuilt with ARP rod bolts. Even if I were going to go with factory BBC rods, I think I'd rebuild them with good bolts. As far as what parts need replacing, major stuff is pistons, cam, and use oversized stainless valves with a little port match and pocket porting. Be sure to use a good machinest and have the rotating ***y balanced. Check for valve spring coil bind. As far as transmissions go, my first choice would be a Richmond 5 speed. If you want a 4 speed a good Super T-10 would work. And to repeat ^^^, check 348-409 website for all the information you could ever need. Larry T
Stock rods aren't all that bad a deal if treated correctly. I built a 421 inch 409 about 30 years ago. I ground the beams, cleaned up around the bolt holes, chamfered all sharp corners, shot peened, ARP fasteners and full floated the pins. Ported heads, larger intakes (don't recall how big..!), single 4 barrel factory manifold (HARD to find back then). Even with the m***ive (and very heavy Jahns pistons)....I had a lot of fun with that car (61 Impala). Drag raced it sorta often at Orange County Raceway (So. Cal.). Lowered with Norris NASCAR wheels under the fenders, "two" sway bars in the front, a big bar in the back, sorta heavy springs. That 4000lb. beast handled like it was a 2500lb. lightweight. John Kilgore (So. Cal.) built me a Switch Pitch (on a momentary switch) T-400 for it. Mike
Thanks, I will look into that website more. Yeah I think I will be fine with a 4 speed but would be nice to have that extra gear. A TKO 500 might be worth getting also.
The 409 crank in a 348 block will not have issues. Some aftermarket connecting rods may on the big end, but nothing some work on the block with a die grinder can't handle. The 409 blocks will need to be clearanced when using the BBC stroke cranks, too. The 348 oil pan will need to be bonked with a ball-peen when using a 409 or longer stroke, but, again, not a big deal.
Okay you may have talked me into it!! So if I use my stock 409 crank can't I just get the longer BB rods? Or do I have to change the crank and the rods? What am I gaining by doing this anyway? Again my goal is 425 crank hp. If I'm not mistaken there were 425 hp cars right from the factory.
With some cars making 425 hp from the factory I don't see a problem hitting that goal with some head work, a good set of pistons and a good cam.
Whatever you do make sure you check for cracks. It seems that most w blocks up here in the northern part of the country are cracked from sitting with weak anti-freeze. My buddy bought a truck 409 last week and its cracked big time just below the deck on the outside of the block. The guy he bought it from has 2 other 348 that he said are cracked sounded kind of common
Clean it up, rebuild if necessary, paint it orange put in the car and you will be fine. Nobody really cares what the heads, compression ratio and rods are. It is a 409. Your not going to race at Bonneville? Maybe a lumpy cam but would not spend a bunch of money but I am not a drag racer. I have learned, that there is always somebody faster and these days it is not that important.
One thing I have not seen mentioned here is one sure way to tell if it is an 348 or an '09. The crank flanges for each have different shapes. The 348 is round, the 409 is bell shaped. The truck engines make good HP if done with good parts, and a good machinist.
Realize I'm a little late to the party, but, according to my old mortec page its not a truck block. 3857655.....348......62-65...Truck<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o> 3857656.....409......64-65<o></o> 3860386.....409......62-64<o></o> 3860387.....348......58<o></o> Supposed to be the most versatile of the 348-409s out there, as far as compatiblity with other heads, and accessories.
I used a 409 truck block in my build for my '55 Chevy. I took a different route and had it bored and stroked to 476 cu in. Used Eddy heads and intake, Ross pistons, Cali crank. Dynoed at 647 hp & 602 lb tq.
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