Cam replacement questions.

[bentpshrods]

  I just pulled the grill out of my 71 cuda to paint it body color.  While the front end is opened up I would like to also swap out the cam.  40 years ago I wanted a street/strip car so I bored the motor .030, and put in the purple shaft cam.(340 A/T, 3.55 gears)  This cam was the 292 dur./.509 lift one.  IIRC this was better set up for a manual trans which I had plans to change over to ,but never did. This cam has a nice lumpy idle which I really like, but has no low range torque with my current set up. Pulls hard from the mid to high range, but I can hardly do a burn out. Have built the trans with a full manual valve body, 3500 stall torque conv.  I have decided to go with the Lunati voodo hyd (dur. 276/284, lift .513/.533. lsa 110/103) and will be putting on my six barrel set up I have. Currently running an Edelbrock air gap with a 770 holly street avenger.headers, TTI Xpipe exh.  I would like to do the swap without pulling the motor. At what lift should I really worry about valve clearance. Do you always recommend dialing in a new cam, and can this be done with the motor still in. Still has the original valve springs (only has 80,000 miles) but I run it pretty hard at times. Not planning on any head work just now as I will be doing a stroker motor soon. Found a 71 340 block to start        but this might take a while.  So should I put on new springs for now and maybe find a set of 308 iron heads till I get the stroker done.   If I need to pull the heads off I might be better off just to pull the motor.   Maybe  ?????

[Chryco Psycho]

depends on the pistons in the engine now , if you have the 10:1 compression with valve reliefs you "should" be fine but it should be checked above .520 lift  .
I Always degree cams , just not worth taking the chance & yes it can be done in car .
Matching springs are a must for fast ramp cams .
It will perform better with the air gap intake over the 6 pack

[Cuda Cody]

What compression is your engine?

[Chryco Psycho]

If you go to the cam i step smaller you should have no worries , the 10:1 piston have reliefs , the lower comp pistons do not so you likely have more clearance with the higher comp pistons

[1 Wild R/T]

Couple suggestions... Save your $$ on the cam for now, wait till you build the stroker..  Your choice but if I were doing this I'd sell the 340 block to someone who really wants a 340 & will pay to much for it, pick up a 89-92 360 roller block & build that as your 408 stroker.... Buy a roller cam instead, the block will be set up for rollers, if the budget is tight you can re-use the original roller lifters...

[nsmall]

Im the guy who knows next to nothing, but a 340 with 3:55 gears, Im thinking it should be relatively easy to spin the tires?  Ive been reading about strokers and it seems like a 360 would save you some money vs a 340, but how much as I have no idea.  Chryco might know the cost difference as I would be interested, I guess it doesnt matter if you already have a 71 block.

Good luck and I hope you find some horse power.

[1 Wild R/T]

The point of doing the 360 has less to do with cost than the final result... Getting more $$$ for the 340 than you pay for the 360 is just a bonus...

[RUNCHARGER]

By the time you purchase a camshaft, lifters, springs etc. i think I would leave it alone if you are going to build a new engine anyway. Also there really is absolutely no benefit to using a 340 block as a stroker. The beauty of the 340 is it's love to rev with a stock stroke crankshaft. A 360 or a 340 have basically the same bore so a stroker crank will build the same CI (within 5 ci anyway). As Wild indicated if you sell the 340 block it will buy you a roller 360 block with $$$ to spare, then if you don't invest anymore money in a cam change you can get this stroker going a lot sooner.
My opinion for what it's worth.
BTW is your distributor recurved with an aggressive advance curve to match the current camshaft?

[nsmall]

Thanks Runcharger.  I didn't know any of that information.

@bentpshrods Do you have an idea of when you can build the stroker?

[303 Mopar]

I agree with the above, sell the 340 and get a 408 stroker.  The 408 in my '71 Challenger really pulled hard and was quick!  The cam was 530" lift and 286/236 duration and had a nice lumpy sound.

[7212Mopar]

I would get a stroker but keep the 340 block if you don't want to build that. They are difficult to find now.

[7212Mopar]

BTW. I think cost of building a stroker with a 340 or 360 block would be the same assuming the engine block needs the same prep. I have a 340 block so I used it and it was good enough to build. My builder was going to get a 360 block for a few hundreds if my 340 turns out bad. A stroker will have more torque and power than a build stock stroke 340. You need good heads to get the most out of a stoker.

[bentpshrods]

  Thanks for the replies.  This gives me some ideas to think about.  Might have to check into going with a complete 360 motor or not.  I ended up with a foot injury that took me out of work for 5 1/2 months so I have a bit of catching up to do.  Won't get it done this summer but shooting for next year.       303 Mopar your car has the kind of lopey sound I like.   

[1 Wild R/T]

Key here is to get a 89-92 360 cause it's got a roller cam.... A retrofit type roller between the cam, the special lifters with tie bars, and all the other parts typically sets you back 12-1500 dollars... A roller 360 with a little searching will set you back less than $300, I recently picked one up for free... And you can reuse the lifters, tie bars & spyder.... A more aggressive roller cam will set you back $350-400....  Hopefully by now we all know why you want to run a roller cam these days....

[Katfish]

Key here is to get a 89-92 360 cause it's got a roller cam.... A retrofit type roller between the cam, the special lifters with tie bars, and all the other parts typically sets you back 12-1500 dollars... A roller 360 with a little searching will set you back less than $300, I recently picked one up for free... And you can reuse the lifters, tie bars & spyder.... A more aggressive roller cam will set you back $350-400....  Hopefully by now we all know why you want to run a roller cam these days....

Hey Wild, all motors in these years the same, car, truck, van?
I'd like a roller build in the future, may start keeping an eye out for a 360.
Any other key things to look for?