re-arch of springs

[evan396]

my dad and i need some advice,the truck is a 1966 k-20 with a six cylinder and we are going to replace it with a sbc 350. we are going to have the springs repaired and rearched. we are pretty sure that the 350 is a little lighter than the six. should the springs be the same height all the way around? we just want to make sure that the truck sits level with the engine swap.we would also like to increace the arch by one to two inches if this would not interfear with the steering. would like to know if we even need to do this if we are going to use 33" tires or maybe 35" tires. jus

t so you guys know, we are going to keep the same driveline and the 3/4 ton axles, just the engine swap. thank you evan396

[swamp rat]

I have no idea what kind of home made spacer blocks are under the rear springs but i'd be thinking about getting rid of them for proper blocks or full arch springs.

I hope there isn't any blocks under the front springs, that is super dangerous.

I don't have an answer about the engine weights but i'd think the 6 cyl to be a bit lighter.

[imjeff]

The weight difference isn't enough to worry about.

[dodgiesdad]

Your rear lift blocks to the best of my knowledge are factory, my 65 has the same set-up. Yes full arch springs would be nice, but also much more pricey. I had mine re arched approximately 1" over stock specs and I do expect the rear to sit a little higher when I am done. It was slightly higher before, I was running a 350 sbc and am putting in a 406 sbc. Also I was running 33's (with no interference) and am planning on staying with the same tire size when it goes back together.

[imjeff]

Originally Posted by dodgiesdad

Your rear lift blocks to the best of my knowledge are factory, my 65 has the same set-up.

Those are factory cast pieces.

[evan396]

Thanks for the replies, from what I have read, the rear blocks are stock with no blocks in front. dogiesdad would you suggest that we raise the front about 1 inch higher than the rear as we would like it to sit level.and if the rear is sitting lower,is it possible to shim it to get it level? Also glad to hear that there is no problems with interference if we run the 33. Thanks again evan396

[imjeff]

I wouldn't add any shims. The stock blocks are borderline, stability wise. Adding anything would add another failure point and torque on the u-bolts. As is, if you put enough torque to that rear end it will want to twist out of the u-bolts. It worked back in the day, but if you upgrade your drivetrain you may want to update that arrangement as well.

[dodgiesdad]

I have agree completely with imjeff although it would be possible to level it with additional shims I would not suggest doing it. I am concerned with my new motor and the factory rear set-up as well, If I were going to be using the truck as a truck or a racer I would be changing that on mine now. But as it is the rear blocks are staying for this go around. I am not sure what to suggest as to the amount of over arch to use to get your truck to set level. I went 1" front and rear. Ask me in a month I may know better then, I hope to have my drive train completed and the body back on by then.

[swamp rat]

Dang I'll stand corrected, never seen that kinda block before, sorry.

[andrewmp6]

I would swap engines and see how it sets then.