I looked all the way back to August and I didn't see this covered so here goes. Has anyone tried to swap one of the late model 5speeds (Mazda?) for the 70's (1979) NP435's? I have a '79 F150 that I would like to put an overdrive unit in. It sounds like a few of you have some of the 4 speed overdrives and you aren't impressed, are they weak trannies, who makes them? I know that the NP 435s are tough trannies and "a truck is a truck" but I would like to lower the RPM's without loosing my rear gears (3.55's I beleive).
For engine buildups, how do you guys like the Offy intakes? I am looking at the dual plane, any recomendations? Any interference problems with headers? I see that a lot of you prefer the SBC valves 1.94/1.60, I am assuming that they flow better but what other alterations need to be done to the valvetrain or the head in order to use these? Is it a simple process to put in the Chevy valves other than grinding out the seats to fit them? Are there any inherent weaknesses in my '79 300 block/heads? LASTLY, do any of you know a good book for building up 300's? This is my first 300 so I am new to this I-6 stuff. Thanks for all of the help!!
Jeremy

 

[updated:LAST EDITED ON 15-Jan-02 AT 03:21 PM (EST)]Hey there!

I'm in the process of fitting my '79 with a Crane cam, and want to open up the head with the same valves. I need to know if the Crane hi-lift springs will work with the Chev valves and which valves are recommended. I've done some research and want to go with the Offy intake, Pacesetter header and Holley 390, all available from JCW which makes it easier for me as I'm in Canada and want just one shipment and Customs invoice to pay. Most of the guys here seem to think the stock ignition will work just fine.

The engine is out of the truck and partially disassembled, I'm prepping the head to go to the machine shop now and need to know what to tell the machinist as far as what valves to install. Once the head is done, I'll get the bottom end done, Christmas really whacked the old Visa card and I can't afford it all at once.

Good luck with your project, I'm going to watch what the guys say with alot of interest.

Cheers!

Les S.
bigsixguy

 

[updated:LAST EDITED ON 15-Jan-02 AT 06:12 PM (EST)] go to hi performance mods on this message board and you can see the problems that I am having with my upgrade. I have a couple of solutions that I am going to try my self first to get the headers to seal up. If they work I will get back to you guys.

 

Good luck with your engine! I decided to skip the headers and go with an '87 EFI exhaust manifold, actually it's a two piece set up. I am also looking at a Crane cam but I won't go the Chevy valve route, that would be more machine work than I can afford! Christmas hit me hard too, gotta get my priorities straight- truck first and wife second!! Right, that would work.
Jeremy