Rebuild heads or No?
Thread Starter
Staging Lane
Joined: Jul 2004
Posts: 52
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Rebuild heads or No? Hey guys I'm new to the forum so go easy on me if these questions have already been asked.
I have a 95 LT1 from a Caprice 9C1 with about 102,000 miles on it I'm transplanting into a Datsun 240Z. Before I pulled the engine I did a compression test and found all cylinders to be from 190 to 195 psi, I also checked 2 rod and 1 main bearing(s) for wear problems and found none. I'm going to put an LT4 Hot Cam in it, should I rebuild the heads when I do? Will I need to replace the valve springs to avoid coil bind with the .490 lift of the Hot Cam? If so would it be more cost effective to have the valve spring seats machined for larger springs or get LT1 iron head specific springs? I've heard these stock springs suck, is this true?
ZcarGuy
I have a 95 LT1 from a Caprice 9C1 with about 102,000 miles on it I'm transplanting into a Datsun 240Z. Before I pulled the engine I did a compression test and found all cylinders to be from 190 to 195 psi, I also checked 2 rod and 1 main bearing(s) for wear problems and found none. I'm going to put an LT4 Hot Cam in it, should I rebuild the heads when I do? Will I need to replace the valve springs to avoid coil bind with the .490 lift of the Hot Cam? If so would it be more cost effective to have the valve spring seats machined for larger springs or get LT1 iron head specific springs? I've heard these stock springs suck, is this true?
ZcarGuy
Last edited by zcarguy; Jul 9, 2004 at 05:51 PM.
not sure what if any differences there are with the iron heads, but with the aluminum heads youll need new springs for the hotcam. as for the heads. id pull them to put new head gaskets on since the einges out and there are right there. while they are out drop some valves and see what the guides look like or take it to a machine shop let them spec them for you. its not hard or expensive. might as well do it while its out of the car. id also replace all the other gaskets and pumps while its out. thats just me though.
Joined: May 2004
Posts: 1,593
Likes: 267
From: Halfway back on the Highway to Hell...again!
If you use the stock iron heads, they will have to be worked to fit the springs for the hot cam spring diameter, plus you will want screw in studs installed. your best bet is to find a set of aluminum heads and have those reworked or buy a set already done.Brian Tooley at Total Engine Airflow does the best I've ever seen and I've been building cylinder heads for about 15 years. His link is on the right---->
His price is $1500 w/ exg. last I checked anyway.
Also, it sounds like you're planning on racing it so your better off to start with new bearings, having the crank mic'd and having the bore gauged. one weak part and there goes the whole motor. Don't guess and take chances. Checking one bearing doesn't tell the story for the entire motor. I had seen too many people take the easy way and ended up doing the hard AND expensive rebuild. "Do it right the first time or don't do it at all"
His price is $1500 w/ exg. last I checked anyway.
Also, it sounds like you're planning on racing it so your better off to start with new bearings, having the crank mic'd and having the bore gauged. one weak part and there goes the whole motor. Don't guess and take chances. Checking one bearing doesn't tell the story for the entire motor. I had seen too many people take the easy way and ended up doing the hard AND expensive rebuild. "Do it right the first time or don't do it at all"
