Maverick and Comet Forum Archives - Maverick/Comet Technical

#1 Maxx Levell 351 Block Power...?  
Whats the consensus on how much HP I can safely throw at a factory 351 roller block? I know on the 5.0's that once you start approaching 550 or so you're living dangerously...Getting ready to make a move to a 351 based engine combo and am just getting a feel for which way to go...

Message created at 10/05/11 02:03 PM
#2 maverick1969 Re:351 Block Power...?  
I was making 670 HP in the 70's with my 1970 4 bolt 351 Cleveland block. It's still making over 500 HP today after a camshaft, head, and a few other changes some years back (had to de-tune for street use). Couldn't say if the Windsor block could do this and live so long. The Cleveland I have is a Boss block with the original high nodularity factory crank. I did change the rods for polished ones and the pistons are TRW 12.97:1 race pistons. I still keep the closed chamber race heads, but use later model open chamber 4V heads now. The 351 Cleveland 4 bolt apparently has no problem making 600 or so horsepower. Just be sure you have a good crank and rods for the power level. A new Cleveland 4 bolt 302 is also available from Ford Racing, but I'm unsure about the 351 4 bolt Cleveland being available.

You might also be interested in the "3V" Aussie aluminum heads if running flat tops or dished pistons. I had thought of using them, but I'd have to pull the TRW domes or be back at 12.97:1 - and not very street friendly. The Aussie head have higher intake runners and some machining should make them very capable in the 600+ horsepower ranges. I noticed "" is offering a set at a low price.
Message created at 10/06/11 01:54 PM
#3 Maxx Levell Re:351 Block Power...?  
Thanks. I already have a set of AFR heads that I'll be well as a Comp Cams solid roller and lifters. Just need a suitable late model block to start with lol. The heads are the 58cc version. I'm looking at doing a 408 stroker. Should bring the CR in right around 13:1. If I can find a running engine, I may just swap out the heads and cam until the season is finished here...which is quickly approaching, and do the stroker over the winter. That would give me an idea of how much the stroker improved the performance. Just depends on locating a useable engine right now.

I've actually located a couple, but not sure if I'll buy. Both are from salvage is already pulled, and comes basically as intake to oil pan without any of the accessories...I think they want $400-450 for it. The other is running in a van at another salvage yard, and they want $400 for it with a warranty, or $250 without warranty or accessories...BUT...I have to pull it, which I don't have time to do lol.

I may ask them about hauling it to my place to remove the engine and then bringing the van back to them so it doesn't have to be done in a field lol. I also may try to talk my son in law and one of his friends into taking it out for me :thumbsup: Either way...I think the time has come to just notch the shock towers and stuff the 351 based combo down in there and LET IT EAT...
Message created at 10/06/11 02:32 PM
#4 maverick1969 Re:351 Block Power...?  
You'll want to be sure you have a 4 bolt block. They were plentiful in old police interceptors and often had the better cranks. When I was racing at the 670 horsepower level, I did frequent teardowns and magnafluxed everything. What I usually encountered and replaced rods for was a loss of big end roundness in those factory rods. I also kept everything fully balanced. Without a full balance job, I wouldn't trust a stock engine of any kind to stay in one piece long under race conditions. Those factory cast pistons aren't going to be much either, in those run of the mill engines you mentioned - but they were fine under 300 horsepower. Just swapping the heads and cam is an invitation to lose a lot of good parts if you plan on any higher RPMs.

The Cleveland engine will fit a stock Maverick front end well (where a 351 Windsor doesn't in the oil pan area), and using a smaller offset starter to clear the the steering rods will give improved clearance there. Notching the towers really isn't enough for the needed large tube headers, and installing and properly routing them is something of a bear. (chuckle) Yeah, I guess I was something of a Grizz when I shoe horned the 351 C into my Maverick back in '72.
Message created at 10/06/11 03:42 PM
#5 maxx levell Re:351 Block Power...?  
It's not looking like I'm going to be able to get anything in and running before the it more than likely will not run without a stroker kit install over the winter.
Message created at 10/06/11 07:57 PM