Picked up a 348 truck engine for my 62 impala project today, block# 3857655, deck stamp TO207xxp. 4 barrel carb, dipstick on the pass. side, head casting ends in 333. Ive done a little searching on improvements but I've never messed with these at all. What should i know before dropping it in the impala? Thinking bumping up compression and a small cam & some home porting. Any advice is welcome.
New w engine owner
- Thread starter chevynut
- Start date
You've got a great start with that "655" block and those "333" heads, assuming they check out OK and are crack free. The oil pan and timing chain cover are keepers as well.
You can port those 333s with some success, others have lead the way on that front.
Several aftermarket intakes are available for those small port heads, that would be a huge improvement over the "truck" cast iron intake.
You can really spice things up by slipping a 409 crank in there, get some new rods and pistons and you'll have a real performer
.
What are your plans for '62? Daily driver? Occasional cruiser? Race car? Something else? Let us know your ambitions and collectively we can offer some insights for you to make good decisions.
Cheers and welcome aboard!
TomK
You can port those 333s with some success, others have lead the way on that front.
Several aftermarket intakes are available for those small port heads, that would be a huge improvement over the "truck" cast iron intake.
You can really spice things up by slipping a 409 crank in there, get some new rods and pistons and you'll have a real performer
.What are your plans for '62? Daily driver? Occasional cruiser? Race car? Something else? Let us know your ambitions and collectively we can offer some insights for you to make good decisions.
Cheers and welcome aboard!
TomK
I don't have any water pump on it, was supposedly broken years ago when the engine was being moved. Links to any similar builds are appreciated, did some searching and have learned a lot these past few weeks. Plans for the 62 are to make it look like a 62 409-4 speed car. I drive my cars a lot so it will see more street time than average. So a 409 rods/crank with 348 bore pistons works? What displacement does that equal?
I wouldn't use the 409 rods,or any cast piston here.Yes,it can be done,but ,imo,it's far to risky from a durability standpoint.Such a packge will also be quite a bit weaker in the one area that your heavy car's going to need,and that you're going to want,torque.There's no reason why you couldn't build one of these 380's,using your heads,to make close to 450 ft.lbs by about 4,000,420 hp.by about 56-5700 rpm that will cruise all day long at 23-2400 rpm at 70 mph.A little porting work,bigger valves,a conservative cam,small tube headers,and a 10-1 compression will get it done.
409 crank,6.385 rods[big block],K-B Icon pistons pn 781-5p30.You're right,the engine has cast pistons in it now.7.75-1 compression.With the aforementioned rotating assembly,properly blueprinted,and your 333 heads,you'll wind up right at 10-1.Do you want it to look kinda-sorta like s 380 horse[single 4bbl],or a 409 hp[2-4bbl.]engine?
Excellent info. By 6.385 do you mean regular BBC chevy rods? I don't have plans for dual carbs just a new intake of some sort and a single carb. Am I correct there is not an original GM intake for duals that fits the small port truck heads? Also is there a best option to send the heads to have work done - there aren't any really good machine shops locally that work on older engines.
Yes,BBC aftermarket rods.Jegs has them in either Eagle or Scat for around 320 per set.There's nothing on these heads that a decent machine shop can't handle.All you'll need is to open up the valve seats up to 2.07 intake,1.72 exhaust,open up the area just below the valves to about 85 percent of the valve size,clean up the ports,and blend it all in.Do not have them install hardened seats! In most cases they aren't necessary when you use stainless steel valves.Yes,you're correct about the intake manifold.Edelbrock makes a very nice manifold for the small port heads in either a single or dual four barrel configuration,I'd go single 4bbl myself,and use the street Demon 625 cfm unit here.As to the cam,I'd go with a Comp Cams unit from Show Cars,pn 0951,and a rear gear of about 3.36 with the standard tire,or 3.55 and a tall tire.Are you planning on a manual or an automatic trans? What part of the country do you live in?
I have a m-21 muncie ill probably use. I run 3.55 gears in my 55 chevy and I like them so that's what I had thought.