I recently got ahold of a 1976 4 door mav with a 302. It recently passed the strict california smog II test, and hydrocarbons were very low on the test, indicating that rings are in pretty good shape. I was told that it was rebuilt somewhat recently and it does run very smooth. What I'm thinking about doing is just leaving the bottom end alone and putting a few parts on the top end to get a little more power out of it when I transplant it from my 4 door to my 2 door project car. I'm not looking for huge horsepower here and I am trying to keep costs to an absolute minimum. One of my ideas would be to get a cheap set of gt-40 heads, maybe an Edelbroch performer intake, a mild cam, a cheap 600 cfm carb (maybe even an autolite one off a continental or something), a set of small tube headers i have laying around my garage, and dual 2.5" exhaust. What do you guys think about these ideas? I think I can get most of these parts pretty cheap, probably can even get the heads at a junkyard as they came on certain mountaineers and explorers. Does anyone know if these heads will definitely work on a 1976 block? Would I have to run a roller cam with these heads, meaning that I would have to modify the block to be able to run the roller cam?
How many miles are on this engine? It kind'a sounds like you're talking about building a "grenade". I'm not aware of any "cheap sets of GT40 heads". If you're going to go to all the trouble you mentioned, you can certainly freshen the bottom-end with rings & bearings. A windage tray is also a good idea, as well as ARP rod bolts (requires machine work to the rods)...
Mileage on engine is unknown. I was told it was rebuilt somewhat recently (30-40k miles ago), but I didn't see anything to verify that. It runs great and the hydrocarbons on the smog test were very low, which indicates my rings are in good shape. This is a somewhat temporary thing, in a few years I plan on building a bad ass EFI motor, so it's not like I'm going to live with this combo forever. I really don't think I will have a problem if I do some mild performance upgrades on it. Anyone have any details on the gt40 heads and what I would have to do to make them work on my 76 block?
GT40s are good heads....but I personally wouldn't waste the money on them if you're planning on upgrading later on. It'd be like spending twice. On the other hand, you could sell the GT40s later on when you're upgrading and use the money for something else, so it's your call. Watch out for those GT40's....the spark plugs are angled funny and sometimes cause header-to-spark plug clearance (or lack thereof) problems.
The GT40 "Ps" are the only ones with funny spark plug angles. The standard GT40s should have normal plug angles. You can find GT40 irons for around $400 or less so they are truly budget heads. They have alot of potential for their price thats for sure. I wouldnt say that hes building a grenade really. Unless hes going to (try to)turn the thing 7000 RPM. I would build it. I would go with the Performer RPM Air-Gap intake, but thats just a personal preference. AC
HEY! Mavman, no problem....I was wondering, do you have some pics of your old turbo setup? I am thinking about building one for my Mav one day. I built a twin setup for a FOX Stang, so I know what needs to be done as far as components, drains, feeds, etc....I just wanna see some pics of a setup in one of our real-estate hogging Mav engine bays Thanks, AC
What's the deal with using a roller cam in an older block? If I remember, you'd have to machine the block to make it all work right. Do you think I could use a set of newer gt 40 heads with an older hydraulic style camshaft? What would you guys recommend?
I dont see why you couldnt use the heads on an older non-roller block. You may have to measure for new pushrods, but I see no reason why they wouldnt work. Personally, I wouldnt bother with the expense or converting a non-roller block to a roller. A 351 maybe, but a 351 has alot more potential than a 302. If you really wanted to have a roller motor, you could buy a low mile shortblock or longblock for around $400-600. Maybe less depending on your area. This would come with forged pistons(depending on year), moly rings, a pretty aggressive roller cam, and all the lifters, spider, etc. Not to mention a swell one piece rear main seal AC
I looked at converting my 68 block to roller ... would have been $800 or so. Special retro roller CAM is expensive and the special lifters are expensive. If your block is already at the machine shop he can drill it to use factory roller lifters and the factory spider hold down and then you just need the retro roller cam and shorter push rods.
Ok so roller cam is out. It doesn't fit with the budget theme at all . Now, could I use a new set of gt 40 heads with an older style Hydraulic? cam? What would I have to do to make those heads work on my 1976 block? If you guys have an experience in this type of thing, let me know.
The GT40s will bolt right up. You will need to check pushrod length though. They are also pedastal mount heads as opposed to stud mount. AC
AC, no I don't have the pics anymore. Everything went when I sold out...including all of the pics so the buyer could piece it all together. His ought to be easier considering it's going on a '67 Mustang w/302. You might try searching the archives.
retro-fitting is VERY simple. You'll have to get all of the lifter retainers (dog-bones), hold down (spider), and two 1/4-20 screws that are about 1/4" long. Put the lifters in the block with the dog bones, set the spider down on top of them where it should be then mark the 2 mounting holes. You'll have to drill the holes and tap them. Just be careful that you don't drill too deep and drill through a cam bearing. I think it's easier to do it before the bearings are installed....that way there's no fear of going too deep and you can just go all the way through. Thats all that's needed as far as machining. When you call a cam company, you'll tell them that it's a retro-fit and you'll need a small base circle cam (custom) which costs a bit more. These days, about all roller cams are in the $230-$300 range depending on make, options, etc. That's all there is to it!
Well darn Oh well, sadder things have happened I suppose. I actually tried searching the archives and came up with nothing. No biggie. AC
