Got the 3.5 heads, think I'm good to go!

[Tomguy]

Ok, I got 3.5 heads (and cams and rockers) in good condition. It looks like it had a valve job recently, as well as new cams and rockers (within 10k miles or less maybe), so I'm not even going to take them apart to do the seals.

I think my compression ratio will be 9.2:1 using these heads. the 8.0:1 heads have ~52.6cc combustion chambers (measured using a non-medical syringe). The 3.5 heads I grabbed are ~38.4cc. The pistons on the 3.5 are very flat, with only very small cutouts for the valves. I used this page with a head gasket thickness of 0.069" (measured a used gasket with my vernier caliper). I played around with the piston dish numbers until I got 8.0:1 with a chamber size of 52.6cc (and of course, the proper bore and stroke numbers), then put in the 38.4 of the 3.5 heads. It gives "9.18" as the ratio. I'm going to go ahead and try this with one gasket (not stacking them). I just ordered the head gaskets, intake and exhaust manifold gaskets, injector seals, and valve cover seals. If, when I take it apart, I find the pistons to be identical in looks to the 3.5's, I will then double-stack the head gaskets, else I'd have 11.95:1 (9.48 with them stacked).

3.5 heads are better than any 4.5 head, and there's still room for improvment in my 4.5 if I find this to be insufficient. I can put the 3.5 pistons in, and double-stack the head gaskets, for a 9.5:1 compression ratio.

Clark (the guy I got them from, locally) also gave me stuff to put on eBay for him. Including an ECU (3.5 specific), MAP sensor, the entire intake manifold assembly (which I will disassemble later and piece out), and other parts.

I'll let you guys know how this whole process works out, including (as always) ample pictures!

[tosbt]

Following with great intrest.

[JMela]

x2. Giddyup!

[j9fd3s]

sweet!

[Tomguy]

Hoping my head gaskets come while I'm at work (Friday) so I can do them before the weekend comes! I'll keep you guys updated. I'm getting antsy!

Go a-head Tom Guy, here in Holland we're very interested in the results.