I know the L29 has a non-adjustable valvetrain, but I got a freebie pullout cam from a Mercruiser 502 with brand new lifters, just want to know if it will work. Here's the specs

Merc# 431-850478 / GM#12551622
.050� 225*/225*
Lift .483�/. 483�
ICL 109*
LSA 115.5*

I understand it's not a huge improvement over stock, but I'm not willing to spend the money for a really good cam on this particular engine. Just need to know if I can just throw this one in while I've got the engine out. This one is just to get my truck going until I get the other 454 fully built.

 

Bueller....Bueller....

 

Im pretty sure you won't get an answer on this forum, that is not a popular engine in the LSX world.

 

how do you plan on re-tuning it once the cam is in?

 

Since it's not much bigger than stock, I figured the factory PCM will still run it and the tune can wait until I can get my 411 harness ready. I know the factory tune won't run it as best as it should, but it should work until I can get the tune

 

I have that same cam in a 454 in a 3500, I replaced the 95 heads with 96 and newer vortec heads that give a full point increase in compression at the same time and didnt have any problems, I did change to adjustable rockers and put rollers on it though. That is a roller cam, is your block set up for that? mine was a very late 95 and had all the threaded bosses in the valley for the factory roller lifters with dogbones and spider hold down. If you dont already, head over to 454ss.com theres alot of good info on this motor over there. Also I replaced the prom style ecm with a "burnable" style from "Dynamic EFI" called the "Ebl Flash" it works just like hptuners for these gen trucks.

 

F-150, the L29 is different than the '95 and earlier. It has MPFI and a factory roller cam. So yes, my block is set up for it. How did you change to adjustable rockers? Just a rocker swap or did you have to drill and tap for screw in studs? The PCM is also different. Thanks for the info though, it will help when we build my friends TBI 454.

 

Although not recommended for a very large cam that requires reasonably healthy valve-springs, there are conversion studs available that will get you from a net lash to an adjustable valve-train configuration. With such a small cam you should be OK, but for anything that has much of an increase in spring pressure, you run the risk of pulling the small conversion studs out of the heads.

 

Yep, You are correct, my bad...my truck actually has the newer block but still has the older tbi top end it was l29 heads i swapped to. Trust me, that was a topic of discussion i finally had to pull it apart to confirm which block i had before i ordered parts. anyway 1bear is correct, i used the conversion stud kit, i "think" it was part #CRN99152-16...They were from Crane, i know this much for sure...sorry it's been about 4 yrs...

 

Not planning on a huge cam 1Bear, it's my daily. Also planning on swapping heads with a set of 781s.
F-150, thank's for the info, always good to have someone who's actually done the work.

Question for all, I have a chamce to pick up a set of almost new Comp 26099-16 springs for VERY cheap. Will these be too tense for my desired setup? Not planning on a huge cam, but still something nice and mild.