pushrod length

[FastGT31]

i was wondering if anyone knew what the pushrod length is if i do the 3400 top-end swap? i dont think my 3.1 pushrods will work, if anyone knows what the correct length needs to be on the new pushrods, i would really appreciate it.

[dbtk2]

I believe if you re-use your stock rocker arms with the new heads you shouldn't need to change pushrods. I didn't change pushrods with my 3100 topend swap on my GP and I've had absolutely no problems in 2200 miles.

Shawn

[FastGT31]

i have a set of cranes 1.5 gold race roller rockeres but plan on using a 1.6 ratio set when i swap the heads

[dbtk2]

I think the only time you will have problems is with the stock rockers from the newer topend. I could be wrong on this though. If you search I believe there are a few posts on this pushrod issue on here. But I don't think it will be a problem.

Shawn

[1988GTU]

There's really never a direct answer to this (That I ever read) .

Most people measure twice, order once.. Unless your measuring skillz owns you.

[FastGT31]

exactly, i have never read anywhere exactly what the length needs to be, if i have to order a special set, i will be sure to post it here

[v6h.o.]

With GEN3 heads, I ran a set of Comp Cams 1.52 and 1.6:1 ratio (over the years) with my Gen 1 fully adjustable rocker studs and gen2 pushrod guide plates and my stock gen2 pushrods. Ran this setup with no issues. valvetrain geometry was close enough to being dead on.

If you are going to be using a set of Crane rockers you may be ok to run stock pushrods. What I would do is set it up to ensure that its damn close or not.

If you are using the GEN3 rocker arms with the GEN3 heads on a GEN2 block you will need custom length pushrods. Which will have to be measured. I special ordered a set for a guy's engine one time and had the measurements once somewhere.... However I know a few other guys who have done the same and when we compared measurements they were all different. Close but different. This is all relevant to which gasket thickness you are using (either the stock .060 thick or the Iron headed version .040) how much the heads have been milled and then just variances from Rockers/Lifters and also just differences between different people measuring.

[Syn]

if your useing gen3 rockers with the gen 3 heads on the gen2 block(hybrid)
the measurements are:
6.26" exhaust and
5.95" intake

haha dbtk2 look i see you on here and thirgen.org


Russ

[FastGT31]

i'll be using crane 1.6 ratio full roller rockers when i do the conversion. i'll measure my pushrods and see how close they are to those measurements and see if i have to order a set.

i appreciate all the info from everyone

[v6h.o.]

The measurements I had were 6.275, and 5.94 inch

Others I know have measured:
6.250 and 5.950 inch

6.260 and 5.94